Lets be frank here, Political limitations are the only thing stopping government agencies from shooting Laser Microphones half-a-mile away listening to your entire house. (4th Amendment, Illegal Search) You have no idea of the abuses that can be possible with law enforcement equipment, and are probably just scared of a little bit of the possibilities or powers afforded to them.
Keep your wits about you, this can get much much worse before it may get better. And hyperbole now will only harm your argument in the long run.
Reality is, intelligence agencies are under DoD. They aren't supposed to be investigating Americans, period. If they manage to nab information about American People (which includes legal immigrants btw), they are not allowed to forward it to law enforcement.
We know that anything pulled out of the NSA system is recorded and checked by the FISA courts, to ensure that Americans were not part of the targets. (Edward Snowden admitted it himself, although he wanted more than just 5% random checks on this log).