Ad blocking or ad filtering is a software capability for blocking or altering online advertising in a web browser, an application or a network. This may be done using browser extensions or other methods. Ad blocking is recommended by the FBI to prevent online scams. History The first ad blocker was Internet Fast Forward, a plugin for the Netscape Navigator browser, developed by PrivNet and released in 1996. The Adblock extension for Firefox was developed in 2002, with Adblock Plus being released in 2006. uBlock (now called uBlock Origin) was first released in 2014. Technologies and native countermeasures Online advertising exists in a variety of forms, including web banners, pictures, animations, embedded audio and video, text, or pop-up windows, and can even employ audio and video autoplay. Many browsers offer some ways to remove or alter advertisements: either by targeting technologies that are used to deliver ads (such as embedded content delivered through browser plug-ins or via HTML5), targeting URLs that are the source of ads, or targeting behaviors characteristic to ads (such as the use of HTML5 AutoPlay of both audio and video). Prevalence Use of mobile and desktop ad blocking software designed to remove traditional advertising grew by 41% worldwide and by 48% in the U.S. between Q2 2014 and Q2 2015. As of Q2 2015, 45 million Americans were using ad blockers. In a survey research study released Q2 2016, Met Facts reported 72 million Americans, 12.8 million adults in the UK, and 13.2 million adults in France were using ad blockers on their PCs, smartphones, or tablet computers. In March 2016, the Internet Advertising Bureau reported that UK ad blocking was already at 22% among people over 18 years old. As of 2021, 27% of US Internet users used ad blocking software, with continued increasing trend since 2014. Among technical audiences the rate of blocking reaches 58% as of 2021. Benefits For users, the benefits of ad blocking software include quicker loading and cleaner looking web pages with fewer distractions, protection from malvertising, stopping intrusive actions from ads, reducing the amount of data downloaded by the user, lower resource waste (bandwidth, CPU, memory, etc.), privacy benefits gained through the exclusion of web tracking, and preventing undesirable websites from making ad revenue out of the user's visit. Blocking ads can also save substantial amounts of electrical energy and lower users' power bills, and additional energy savings can