PRISM is the system and database monitoring all US electronic communications.[http://gizmodo.com/what-is-prism-511875267]
Create a federal law stating that any and all individuals who order, authorize or uses the PRISM system or its data for anything except preventing imminent US terror plots and attacks [including but not limited to: regular crime investigations, political research, embarrassing media leaks, personal curiosity, etc.] shall face a Federal Felony charge of Treason [https://en.wikipedia.org/wiki/Treason#Federal].
The US Government has assured us that PRISM is a valuable tool for stopping terrorism and asks us to "trust them" it will not be used for any other purpose. This law would earn the public's trust.