Police in Springfield, Illinois set up a sign on Interstate 55 announcing a non-existent drug-enforcement checkpoint. The intent was to entrap any motorist who attempted legally to turn off into a rest area in an effort to avoid the hassle of the roadblock. Those motorists who did so were then subjected to a warrantless search for drugs.

"It's just an investigation tool that we use in order to try and make Illinois a safer place," police Lieutenant Brendan Heffner explained to the Rockville Register Star. "These are citizen contacts. At a rest area, people are there on their own volition. This would almost be similar to details at bus stations, where you talk to people at bus stations and train stations and things of this nature where you speak to people."

"The interaction that people feel in those circumstances is not as friendly and uneventful as perhaps the police have suggested," said Ed Yohnka, spokesman for the Illinois branch of the American Civil Liberties Union.