Coming just weeks after a Missouri Fusion Center bulletin warned of "rightwing extremists and militia members" supporting certain political parties, a political activist was detained by airport security after screeners spotted a metal box containing money. According to Bierfeldt, the money was the proceeds raised from selling campaign merchandise at a regional conference.

Steve Bierfeldt, director of development for the Campaign for Liberty, was questioned for nearly a half hour by Transportation Security Administration (TSA) officials about the $4,700 he was carrying. Alleging that Bierfeldt was "subjected to harassing interrogation, and unlawfully detained", the ACLU, has filed a lawsuit against Secretary of Homeland Security Janet Napolitano, whose department includes the TSA.

Bierfeldt was stopped by TSA officials on March 29, 2009 at the Lambert-St. Louis (Missouri) International Airport and detained in a small room. Before he was questioned about the money, Bierfeldt activated his cell phone, which recorded the conversation between him and TSA officials. The recording reveals at least one TSA official berating Bierfeldt and others questioning him about why he was carrying the money. Eventually, one official concluded the money was related to a political campaign and released Bierfeldt. 

The ACLU alleges that airport security officials should cease unreasonable searches and detentions that violate constitutional rights. Larry Schwartztol, a staff attorney with the ACLU National Security Project, said, "Just as the Constitution prevents the police on the street from conducting freewheeling searches in the hopes of uncovering wrongdoing, it protects travelers from the kind of treatment Mr. Bierfeldt suffered."