What's worse, the NSA can pass on what the DEA will claim are anonymous tips that lead to evidence that lead to searches, etc. We become a society of "find me the man and I'll show you the crime" but with a stronger illusion to the rule of law than Stalin was able to muster.
They are already doing this. The NSA gives the DEA information, which the DEA then hides from everyone, including judges, and uses it to build a parallel case against the people the NSA spied on.
Just for the record, I chose that example because I was aware of the fact it was happening.
The scary thing though is that this means that people the NSA doesn't like can find themselves at the center of whatever scrutiny they think is most appropriate.
