Increasingly law enforcement agencies and security services make use of criminal profiles by which to determine which people at security checking points should be subjected to more stringent searches. The profiles are sets of characteristics that are perfectly innocent in themselves, but when taken together are considered clues to identifying security risks, smugglers or the like. The profiles are necessarily treated as classified information. Since the profiles are based on statistical probabilities, a percentage of innocent people fitting them tend to be stopped on a regular basis and subject to searches (often quite humiliating).