Washington ( CNN ) -- A federal appeals court ruled Friday the Transportation Security Administration can still use full-body scanners at airports , but said the agency erred in how it deployed the controversial machines . A privacy group , the Electronic Privacy Information Center , had sued the TSA claiming the machines violated Fourth Amendment protections against unreasonable searches . The group further argued that the TSA did not follow the required procedures before making significant policy changes , such as subjecting travelers to the full-body scanners . The three-judge panel of the U.S. Court of Appeals in Washington rejected the first argument , concluding that there was no violation on constitutional grounds . But they agreed on the second point , saying TSA must now go through proper procedures -- though the court , significantly , did not order the agency to stop using the machines immediately . There is an `` obvious need for the TSA to continue its airport security operations without interruption , '' the judges ruled . Either side can appeal to the full appeals court or the Supreme Court . But another , more likely scenario is that TSA , which is part of the Department of Homeland Security , will go through the public comment and rule-making process . The agency 's decision following that process could then become the basis for future lawsuits . `` This is not over by any means , '' said Marc Rotenberg , executive director of the Electronic Privacy Information Center . TSA officers operate more than 500 of the body imaging machines , which can see through clothes and reveal concealed objects , including bombs and bomb components . TSA plans to have more than 1,000 machines in use at airports nationwide by the end of this year . Passengers are not required to submit to the scans , and may opt for pat-downs . But , the court noted , `` many passengers ... remain unaware of this right , and some who have exercised the right have complained that the resulting pat-down was unnecessarily aggressive . '' The Electronic Privacy Information Center argued that the scanners violate passengers ' Fourth Amendment rights because , the group claimed , the search is more invasive than necessary to detect weapons or explosives . But the court said the government must weigh `` the degree to which ( the search ) intrudes upon an individual 's privacy and ... the degree to which it is needed for the promotion of legitimate governmental interests . '' `` The balance clearly favors the government here , '' the court said . Yet the judges took a swipe at the TSA 's argument that its plans to implement the technology did not merit a formal public comment and rule-making process . `` It is clear that by producing an image of the unclothed passenger , an ( Automated Imaging Technology ) scanner intrudes upon his or her personal privacy in a way a magnetometer does not , '' the court noted . The court also debunked the privacy group 's allegation in its lawsuit that TSA had violated the Video Voyeurism Prevention Act . The judges also labeled as `` silly '' the claim that the federal agency is not engaged in law enforcement . The TSA said in a statement that it is reviewing the ruling . Rotenberg , meanwhile , called the court 's decision important and said it `` pins '' down TSA to a policy in which body scans are optional . Privacy advocates had worried the use of scanners could become mandatory , as they become more ubiquitous at airports . `` I think the court would have had a very different conclusion '' had body scans been mandatory , Rotenberg said .
A U.S. appeals court weighs in on a lawsuit against the TSA over full-body scanners . The panel rules the machines do n't violate protections against unreasonable searches . Judges find the TSA did not go through the right process before deploying the machines .