Image copyright Changzhou First International Trade Image caption The Chinese firm calls its vehicles "surfing electric scooters" 
 
 US marshals have raided a Chinese hoverboard-maker's stand at the CES tech show in Las Vegas. 
 
 The officials confiscated all the company's one-wheeled vehicles and took down its signs after a Silicon Valley-based rival filed a patent infringement claim. 
 
 The case is set to return to court in a week's time. 
 
 The Chinese firm, Changzhou First International Trade, told the BBC it did not believe it had broken the law. 
 
 It claimed it had developed its hoverboard a long time ago and had hidden it until now to avoid it being copied by other Chinese firms. It added that this was the first time it had been involved in such an incident. 
 
 A spokeswoman for the US Department of Justice told the BBC: "A court order has been served in a civil case involving private litigation." 
 
 She added that while it was not uncommon for the US marshals to be involved in such action, she could not recall another case happening at a trade show. 
 
 Media playback is unsupported on your device Media caption Click's Spencer Kelly took a ride on a Onewheel in 2014 
 
 Footage of the incident has been posted online by the news agency Bloomberg. 
 
 Restraining order 
 
 While there are many companies exhibiting hoverboards at CES, the Chinese firm's models - which it calls Surfing Electric Scooters - were unusual for having a single central wheel rather than one at each end. 
 
 This is similar to California-based Future Motion's Onewheel vehicle, which uses sensors and computer controls to keep the board balanced. 
 
 Image copyright US Patents Office Image caption A design patent for Future Motion's design was issued on Tuesday 
 
 "We have design and utility patents that cover our invention," Future Motion's founder Kyle Doerksen told the BBC. 
 
 "When we got word that a company was exhibiting a knock-off product, we engaged in the formal process, which involved sending a cease and desist letter and then getting a restraining order, which was then enforced by the US marshals. 
 
 "As a company that launched ourselves at CES two years ago, we know that the world is watching. 
 
 "And we knew that this was a situation where they could do real damage to our business if we just allowed them to violate our patents." 
 
 Changzhou currently lists its device for $550 (£375) on the Alibaba shopping site, which is about a third of the price of the Onewheel. 
 
 Image copyright Future Motion Image caption Future Motion alleges that its designs have been illegally copied 
 
 There are two patents involved in the case: 
 
 One for the design of the Onewheel vehicle, which was only issued earlier this month 
 
 The other, setting out methods to make the skateboard self-stabilising, which was filed in April 2014 
 
 "Punitive measures could include a permanent injunction preventing Changzhou from selling the product in the US, monetary damages including lost profits we can prove due to infringing sales, and even attorney's fees if the court decides it's an exceptionally egregious case of wilful patent infringement," said Future Motion's lawyer Shawn Kolitch. 
 
 He added that Future Motion had patents pending elsewhere including in China, which it hoped to obtain in order to stop Changzhou manufacturing the device. 
 
 Image copyright Alibaba Image caption Changzhou advertises its CES appearance on its Alibaba listing, which says it can ship them worldwide 
 
 Safety risks 
 
 This is not the first controversy hoverboards have faced at CES. 
 
 Ahead of the event starting, its organiser announced that attendees were banned from using any type of the vehicles to get about its showfloors. 
 
 Dozens of universities and other institutions in the US had earlier banned their use and most of the country's airlines have also refused to carry them. 
 
 The problem is two-fold. 
 
 They have been involved in incidents where people have been injured or killed when the rider lost control. 
 
 And some of the gadgets have burst into flames as a result of problems with their batteries, leading to concerns that some manufacturers are not following safety standards. 
 
 Read and watch more from CES and follow the BBC team covering the event on Twitter. ||||| Info + pre-order at www.rideonewheel.com 
 
 Follow us on twitter @RideOnewheel, like us on Facebook. High res press images are available in our press kit. 
 
 THANK YOU! 
 
 Thanks to all our Backers for an amazing Kickstarter campaign. We absolutely crushed our goals and couldn't have done it without you! We have an exciting several months ahead of us and are glad you are joining us on this journey! 
 
 -Onewheel Team 
 
 STRETCH GOALS 
 
 UPDATE: We just unlocked the Onewheel iPhone + Android apps stretch goal. Wow! This is so exciting because it will allow us to enable some awesome new features that wouldn't be possible without the app. 
 
 The apps connect to Onewheel via Bluetooth 4.0. We're still designing them, but some features we're planning to include are: selecting different riding modes, top speed limiting, tracking ride activity through GPS, and sharing with friends, locking the Onewheel, and more. 
 
 Onewheel iPhone + Android apps enable customization and monitoring of your Onewheel. 
 
 Integrated LED Lighting illuminates the way for night riding and provides ‘ground-effect’ illumination. 
 
 DO YOU DREAM OF HOVERBOARDS? 
 
 Onewheel started with a vision of the future--one where fast, fun, electric transportation makes getting around our cities a joy. Then we spent a ton of time putting together the best technologies we could buy and inventing the ones we couldn't. 
 
 What the press is saying about Onewheel: 
 
 "... the sort of gem that brings me to CES each year" -- CBS News 
 
 "Of all the new inventions I came across at this year’s CES in Las Vegas, Onewheel was the most innovative." -- Yahoo News 
 
 "The coolest thing I saw at CES was the Onewheel — a self-balancing, one-wheeled, motorized skateboard." -- TechCrunch 
 
 "Onewheel self-balancing electric skateboard is the closest thing to a hoverboard you can ride." -- stuff.tv 
 
 "we like that there’s only one moving part--the wheel--so there aren’t any gears or chains to mess with." -- Popular Science 
 
 "I don't know about you, but I know that when I pop out on my electric skateboard to do a spot of shopping, I always find myself thinking 'hello – this would even more exciting with three fewer wheels.' Apparently the people at California's Future Motion agree" -- Gizmag 
 
 "the Onewheel seems incredibly lithe; all of its components are stored within the billet-aluminum-and-maple plank, giving it a sleek aesthetic." -- Engadget 
 
 "CES reveals the near future's most incredible toys From mini drones to jumping cars and electric skateboards, a new generation of toys will be on wish lists next Christmas." -- The Guardian 
 
 ONEWHEEL IS A NEW ELECTRIC BOARDSPORT 
 
 Onewheel makes advanced technology invisible. With self-balancing technology, just lean forward to speed up, lean back to slow down. 
 
 REVOLUTIONIZING THE EXPERIENCE OF RIDING 
 
 Onewheel has the most advanced motion sensing, hub motor and battery technology available--you just won't see it. What you'll experience is a board that feels magical whether for fun, waiting for the surf to come up, or getting around town. 
 
 AN INCREDIBLE FEELING - FUN! 
 
 Riding Onewheel is like surfing or snowboarding -- no ocean or mountain required. It gives you that sublime feeling of snowboarding on a fresh powder day. Or that rush when you surf the perfect wave. Except you can do it anyday, anywhere. Get some flat ground and start riding. 
 
 Onewheeling with pro kitesurfer Gretta Kruesi (@grettakruesi) 
 
 RIDE RIGHT AWAY 
 
 Most people can learn to ride Onewheel in a couple minutes even if they're not used to boardsports. That's because controlling a Onewheel is so intuitive. Powerful sensors and sophisticated algorithms are constantly helping you balance and control your ride with just the forward or backward lean of your body. People with experience with other boardsports are often ready to ride aggressively within their first few minutes on Onewheel. 
 
 SPECIFICATIONS 
 
 We took the best available technologies and combined them to create a truly unique electric vehicle ride experience. 
 
 Battery: 48V Lithium Nano-phosphate. The best batteries on the market with the maximum power density, fast charging and best overall lifetime 
 
 Control electronics: Custom 6 DOF MEMS IMU and BLDC driver. Self balancing using PID control system. 
 
 Motor: Hub motor, direct drive. After 3 years of refinement, the design became simpler and simpler. There's literally only one moving part--the wheel. No gears, belts or chains to maintain. The direct drive motor provides power and stability. 
 
 Speed: up to 12 MPH 
 
 Range: 4-6 miles (varies with terrain and riding style) 
 
 Recharging time: 20 minutes (ultra charger) 2 hrs (standard charger) 
 
 FEEDBACK FROM OUR BETA RIDERS 
 
 "Every street becomes like a fresh powder run" -- Gentry U. 
 
 "First it's like, ok I lean forward to go. Then it's like oh, ah, I can lean to steer. Then it's like wwwhhheeee!!!" -- Joe W. 
 
 "Riding Onewheel was like having a psychic under your feet - it anticipated your next move almost before you knew you wanted to make it." -- Annie S. 
 
 A DIGITAL VEHICLE 
 
 The ride experience of Onewheel is controlled by an algorithm we’ve been perfecting for years. Gyro and accelerometer sensors feed a powerful processor that determines the exact speed to drive the motor based on how you lean your body. State of the art power electronics give you smooth and responsive acceleration and regenerative braking. 
 
 FULLY CHARGED IN 20 MINUTES 
 
 Minute-for-minute fast charging with the High-Speed Charger lets you charge in a café or anywhere with a standard outlet. 
 
 Standard Charger: fully charge in 2 hours. 
 
 High-Speed Charger: fully charge in 20 minutes. 
 
 REFINING THE RIDE 
 
 We began with a vision of bringing the amazing feeling of snowboarding on powder to the streets of the Bay Area in the Summer. This was the beginning of an odyssey that led us to being able to open up this technology to the world on Kickstarter. 
 
 We’re riding our 5th generation Onewheel prototypes and we have a couple more iterations planned before our production run. Each iteration improves performance and manufacturability. 
 
 HIGHEST QUALITY MATERIALS 
 
 The frame of Onewheel is CNC machined from solid billet 6061 aluminum. This creates the lightest and strongest vehicle. 
 
 The motor is a unique design, integrated into the hub of the wheel, and manufactured to a very high standard of performance and finish 
 
 The deck is made from high-quality Canadian maple, just like the finest skateboards. 
 
 We've spent a lot of time tuning the hardware and algorithms to give Onewheel a fantastic combination of power and maneuverability. 
 
 A TEAM WITH HARDWARE EXPERIENCE 
 
 The team behind Onewheel has been developing electromechanical consumer and medical products for over eight years for companies like Steelcase, Medtronic and Motorola. They hold degrees from Stanford, and have a passion for electric vehicles. Inventor Kyle Doerksen did the electric vehicle architecture for Faraday Bikes. 
 
 Onewheel Test Pilot Dan Goodwin (left) and Onewheel Inventor Kyle Doerksen (right) 
 
 MADE (AWESOME) IN THE USA 
 
 America is an ideal place for advanced manufacturing. So we’re working with a local contract manufacturer that builds medical and aerospace hardware to build the highest quality product and get this sophisticated product to market quickly. We've already selected most of our component suppliers for production, with many in the USA, as well as some in Europe and Asia. 
 
 WHAT WE'RE DOING NEXT 
 
 We're continuing making Onewheel better and better. With our Kickstarter supporters' backing we'll be finalizing the engineering and setting up our production system. 
 
 WE NEED YOUR HELP TO MAKE THE FUTURE AWESOME, KICKSTARTER! 
 
 Kickstarter is a place where people who can imagine an amazing future help make that future happen. We need help from visionaries like you to launch a revolutionary product like Onewheel! 
 
 You want to ride, right? Kickstarter is the only place to get Onewheel. 
 
 Our funding goal is based on placing orders with our suppliers for parts to build a minimum of 100 units, which will let us tool up and achieve economies of scale. 
 
 REWARDS: 
 
 For a pledge of $1, get your name on the Onewheel Visionaries section of our website. 
 
 For a pledge of $10, receive a die-cut Onewheel sticker. 
 
 For a pledge of $25, receive a Onewheel poster (12"x24"). 
 
 For a pledge of $35, receive a Onewheel "O" Flexfit hat. 
 
 For a pledge of $40, receive a Onewheel logo t-shirt. 
 
 For a pledge of $100, receive a Onewheel "O" logo hoodie. 
 
 For a pledge of $1,299, receive a Onewheel from the first production run. Support the dream, get it first and get a significant discount from the retail price after Kickstarter. Blue. 
 
 For a pledge of $1,399, receive a Onewheel from the first production run PLUS Ultra Charger upgrade (20 minute charge time!). Support the dream, get it first, charge it fast and get a significant discount from the retail price after Kickstarter. Blue framerails. 
 
 Want it sooner? For a pledge of $1,799 you can get Onewheel + Ultra Charger, AND get it before everyone else. Only available to SF Bay Area residents. 
 
 For a pledge of $1,699, receive a Onewheel Custom Edition from the first production run in your choice of ELECTRIC PINK or MATTE BLACK limited edition colors PLUS High Speed Charger upgrade (20 minute charge time!) Only on Kickstarter! 
 
 Custom colors: Electric Pink, Matte Black (both look awesome!) 
 
 PRODUCTION SCHEDULE 
 
 SAFETY 
 
 We've spent a lot of time perfecting Onewheel, but it's a powerful machine and an exciting ride. That means you can still fall, and potentially hurt yourself or others or worse. Always wear personal protective gear, don't ride outside your limits, learn in a safe environment and use common sense. 
 
 LEGALITY 
 
 Laws and regulations regarding electric vehicles, and electric skateboards, vary by country, state, county, and municipality, so please check the legal status of this product before you ride it. 
 
 SHIPPING 
 
 Our rewards include delivery to the contiguous 48 states. Due to lithium batteries and restrictions on shipping methods, we will require Alaskan, Hawaiian, and international backers (whose reward includes a Onewheel) to pay the cost of shipping minus a $50 credit. We will contact you after you back our project to arrange. International backers will also be responsible for all duties, customs fees, and taxes for their orders. 
 
 THANKS TO: 
 
 @grettakruesi, pro kitesurfer and Onewheel rider.
– Hoverboards are making headlines, from bursting into flames and being banned by online retailers to causing trouble in churches and supermarkets. But the hoverboard hubbub at CES in Las Vegas Thursday was something straight out of a corporate espionage movie: Per Bloomberg, US marshals raided a booth set up by Chinese company Changzhou First International Trade. It was promoting its Trotter electronic skateboard—what Bloomberg describes as looking "like a seesaw with one big wheel in the middle." The problem: Silicon Valley startup Future Motion says the product is a knockoff of its own Onewheel skateboard, invented and designed by Kyle Doerksen. "When we got word that a company was exhibiting a knock-off product, we engaged in the formal process, which involved sending a cease and desist letter and ... getting a restraining order ... then enforced by the US marshals," Doerksen tells the BBC. The marshals who swept into the booth scooped up a Trotter, plus marketing material. A quick visual comparison of Future Motion's product and those hawked by Changzhou on Alibaba does show a marked similarity. But while Future Motion sells its version for $1,500, the knockoffs are going for around $550 each—which Doerksen says is bad news for not only his company, but the hoverboard/electric skateboard industry overall. "If customers start to view the space as full of low-quality, low-cost products, that reflects poorly on everybody," he tells Bloomberg. Future Motion, which the business site notes started the patent process for parts of its Onewheel years ago, didn't set up a booth at the consumer electronics forum this year, but Doerksen was in town meeting with possible partners. (Even Wiz Khalifa has had hoverboard issues.)