Sigh...it's much worse than you realize.
The US DOJ has a set of published plans out to lie to the courts in systematic fashion, that have been leaked. It's called "parallel construction":
http://www.washingtonpost.com/blogs/...overing-it-up/
https://www.eff.org/deeplinks/2013/0...nce-laundering
http://www.reuters.com/article/2013/...97409R20130805
Short form: NSA illegal snooping finds you doing something naughty, maybe in a "breaking bad" sense. They learn you're going to turn over a bucket of pot to a buddy at midnight in the parking lot of a strip club.
NSA hands that to the drug war cops at DEA. DEA tail you to where you're dropping off the pot and come up with some reason to pull you over - or make one up. Whatever. They claim to "smell drugs", bring a doggie over, you're busted.
YOU think it was just bad luck, not realizing the entire arrest and evidence must be thrown out under clear US case law on illegal searches and seizures. But you have no way of knowing that you've been illegally snooped on.
The DEA is supposed to turn over what really happened to the prosecutors, who are in turn required to turn that over to your lawyers as "Brady material". But the DEA had a
formal plan in place to violate this to preserve the secrecy of illegal evidence gathering.
Again: this is not theory, it's not speculation, we have the actual secret agreements under which they pull this stunt - a literal conspiracy to lie to every judge and defense attorney in the country in a systematic and illegal fashion.