My question to the OP: even if you believe that at the moment abuses are rare and that your colleagues are trustworthy and law-abiding, does the capability and level of information concern you in terms of the potential for future abuse it enables?
http://en.wikipedia.org/wiki/Project_MINARET#Domestic_target...
* 1980-present. MAIN CORE, which is shared between CIA, FBI, NSA, Contains data on 8 million Americans and is used by LE. http://en.wikipedia.org/wiki/Main_Core
* ?-Present the DEA SOD program which uses NSA intelligence for drug cases. http://www.washingtonpost.com/blogs/the-switch/wp/2013/08/05...
And these are just the cases we know about, they are likely only the tip of the iceberg.
Lorendsr, given this evidence and your previous statements that, "If I thought there was much chance that in the future, law enforcement and intelligence would not remain separate, my decision would change.", are you considering changing your decision?
>FISA surveillance was originally supposed to be used only in certain specific, authorized national security investigations, but information sharing rules implemented after 9/11 allows the NSA to hand over information to traditional domestic law-enforcement agencies, without any connection to terrorism or national security investigations.
https://www.eff.org/deeplinks/2013/08/dea-and-nsa-team-intel...
What this means is that if a given surveillance transcript is obtained legally (which is easy to do for foreign communications, even if a U.S. person is a party to the conversation), that it can be legally passed to LE. Once LE knows about it, they don't have to "close their eyes" to any U.S. nationals on the transcript, similar to how the police are not required to ignore evidence in plain sight (even if it wasn't listed specifically on the warrant).
By this route it is possible to pass incriminating evidence to LE about U.S. nationals even without a warrant, as long as one of the parties to the communication in question is actually a foreigner.