Klayman v. Obama (2013)Issue: Attorney Larry Klayman filed a lawsuit challenging the NSA’s bulk data collection program under Section 215 of the PATRIOT Act, arguing that it violated the Fourth Amendment.

Outcome: U.S. District Judge Richard Leon ruled that the NSA’s metadata collection program was likely unconstitutional under the Fourth Amendment. He issued a preliminary injunction but stayed it pending appeal. In his opinion, Judge Leon called the program "almost Orwellian."

Impact: The case contributed to the growing legal and public opposition to mass surveillance but did not result in an immediate halt to the program.