Drones both dazzled and worried senators at a hearing Wednesday about their use within the United States , and lawmakers and experts said that new legislation may be needed to protect the privacy and safety of citizens . Judiciary Committee Chairman Patrick Leahy , D-Vermont , held and studied a small plane weighing just 2 pounds before beginning the hearing . `` I am convinced that the domestic use of drones to conduct surveillance and collect other information will have a broad and significant impact on the everyday lives of millions of Americans , '' said Leahy . Sen. Charles Grassley of Iowa , the ranking Republican on the panel , said the technology may require lawmakers to develop a new definition of an unreasonable search , which is banned under the Constitution 's Fourth Amendment . Opinion : Do n't give medals for drone attacks . `` The thought of government drones buzzing overhead monitoring the activities of law-abiding citizens runs contrary to the notion of what it means to live in a free society , '' Grassley said . The small aircraft can be fitted with lightweight cameras . Amie Stepanovich , of the Electronic Privacy Information Center , said law enforcement should not use drones as an alternative to police patrols . She said that they should be used for specific operations and that Congress should pass a law requiring legal permission . `` I think we do need to enforce a warrant requirement for drones in circumstances where they 're collecting criminal evidence , '' Stepanovich said . She said exceptions could be made for emergencies . `` With the ease and availability of drones , I think there is a real concern that the day-to-day conduct of American citizens going about their business might be monitored , catalogued and recorded by the federal government , '' said Sen. Ted Cruz , R-Texas . Privacy laws need to be updated to account for drones and other new technologies , according to Ryan Calo , of the University of Washington Law School . Five questions : Targeting Americans on U.S. soil . `` There 's very little in American privacy law that would limit the domestic use of drones for surveillance , '' Calo said . Calo said he thinks the aircraft can be extremely beneficial but warned that Americans may oppose their use unless there are some limits . An industry representative said the federal government already is regulating unmanned aircraft systems , the name industry uses for the aircraft . `` The ( Federal Aviation Administration ) strictly regulates who , where , when and why unmanned aircraft will be flown , '' said Michael Toscano , president and CEO of the Association for Unmanned Vehicle Systems International . He said operators of planes must get a certificate of authorization from the FAA , and the craft are to be flown under 400 feet and primarily in daytime hours . The FAA is supposed to allow widespread use of domestic drones in 2015 . There is only limited use by civilians at present . Because they are cheaper to use than helicopters , unmanned aircraft can be used to monitor crops and livestock , look at damage to buildings and for other uses . The FAA recently announced plans to create six drone test sites around the country . The Mesa County Sheriff '' s Office in Colorado already uses drones . Benjamin Miller said the craft can help find missing people and photograph crime scenes . Miller noted it 's not legal to arm domestic drones . `` It may well not be legal to carry any munitions on a drone , '' said Senator Dianne Feinstein , D-California . `` But what can be done illegally , and how can the government prevent that from happening ? '' Sen. Amy Klobuchar , D-Minnesota , expressed concern that as drones are more commonly used , they could be involved in accidents . `` What would happen if one of them hit a small plane ? '' asked Klobuchar . `` Like when birds hit a plane , it can create problems . '' Toscano replied , `` If there were a collision , then there could be damage . '' Drone came within 200 feet of airliner over New York .
Increasing use of drones in U.S. raises privacy concerns at Senate hearing . Their use may require new definition of unreasonable search , Sen. Grassley says . Drone industry expert says the FAA has strict rules about using the aircraft . Comment: