( CNN ) -- Police drones circling overhead , ready to help search for lost children , rescue stranded boaters and capture criminals . Or drones equipped with lethal weapons , high-tech cameras able to see through clothing , and technology that monitors a person 's visit to religious or political events . Those were divergent and tricky scenarios discussed at a congressional hearing on Thursday ( October 25 ) , as lawmakers contemplated a market that experts believe could grow to 10,000 unmanned aircraft in five years . Congress has ordered the Federal Aviation Administration to develop plans to integrate them into the national airspace system used by jetliners , private and military planes , helicopters and blimps by 2015 . But there are challenges with safety and operations with anticipated police , homeland security , private and commercial use . Privacy , another concern , was looked at closely at the congressional field hearing in Texas . `` We need to establish clear guidelines about when and for what purpose law enforcement agencies , private citizens , and businesses can use drones , '' said Rep. Ted Poe , a Texas Republican and chairman of the House Judiciary subcommittee on crime , terrorism , and homeland security . In many respects , privacy issues involving drones are no different than those presented by other aircraft and satellites , experts said . But traditional aircraft are costly and expensive to maintain , placing natural limits on their use . The low cost of drones will `` erode that natural limit , '' allowing governments to conduct regular surveillance on people , said Chris Calabrese , legislative counsel for the American Civil Liberties Union . `` As the number of drones rises , so , too , will the number of suspects , '' said Rep. Hank Johnson , a Georgia Democrat . `` During the civil rights movement , would activists have left their homes if they knew '' they were being monitored from cameras 30,000 feet above ? '' he asked . `` If we take a Laissez-faire attitude towards this , we will see an erosion of our liberties , '' Johnson said . Experts testified that Supreme Court case law regarding police aerial surveillance relies heavily on the concept of the public 's `` reasonable expectation '' of privacy . But those expectations will change as drones become more commonplace , said David Leebron , president of Rice University and former Dean of Columbia Law School . `` As technology changes , if we take no action , so do our expectations , '' Leebron said . So several witnesses at the hearing said a legislative fix is needed to uphold current standards of privacy . A bill introduced by Poe would prohibit the FAA from issuing a drone permit for use by law enforcement unless it is related to a warrant for the investigation of a felony , with some exceptions . It also would prohibit individuals from conducting surveillance on private individuals or private property without the owner 's consent . `` We must decide now when drones can and can not be used in order to ensure constitutional safeguards , '' Poe said . `` Technology may change with time , but the Constitution does not . '' But others cautioned against action that could stifle industry . `` I think we 're at the birth of this technology , '' said David Crump , a professor at the Houston University Law Center . `` It 's true that it 's exploding ; it 's a very fast growing baby , '' he said , `` But we would n't want to tell Alexander Graham Bell at the birth of the telephone '' to stop development because of privacy concerns .
Safety , homeland security , and see growing market for drones domestically . Concerns about safety , operations and security if drones proliferate in United States . Congress had anticipated growing market ; it would spell out certain goals .