Lawyers for a U.S. citizen charged with terrorism in Chicago say the government is dodging questions about whether it used expanded secret surveillance programs against their client in an effort to ensure those hotly debated practices can't be challenged in the Supreme Court.

The claim came in a filing early Friday in Chicago federal court by Adel Daoud's defense. The 19-year-old is accused of trying to ignite what he thought was a car bomb outside a Chicago bar.

Prosecutors won't say if they used expanded surveillance programs in their investigation. Recent leaks revealed a program that gathers phone records and another that tracks Internet use.

Daoud's attorneys say the government's refusal to confirm or deny use of the programs deprives them of their right to challenge their constitutionality.