“In a cold consent encounter, a person is stopped if an agent thinks that person’s behavior fits a drug courier profile. Or an agent can stop a person cold ‘based on no particular behavior,’ according to the Inspector General report. The agent then asks the people they have stopped for consent to question them and sometimes to search their possessions as well. By gaining consent, law enforcement officers can bypass the need for a warrant. While many people who believe they have nothing to hide may–inadvisably–consent to a police search, they may not be familiar with federal civil asset forfeiture laws, which give federal agents wide latitude to seize property, especially cash, without charging anyone.”
http://www.cato.org/blog/dea-cold-consent-encounters-constitute-federal-stop-frisk