There are plenty of checks and balances against a local national guard violating posse comitatus, namely that the federal government would then send in the rest of the army - all of whom are sworn to protect and defend America and its citizens - to right the situation.
The problem with the NSA is that if they are abusing their power, nobody will ever know about it, because everybody they deal with is sworn to secrecy. Abuses are far more likely to happen in this situation, not because of any inherent maliciousness, but because whenever you have a large organization that never has to face an opposing viewpoint you end up with groupthink and a large possibility of ill-considered decisions.
I'd be satisfied with detailed congressional oversight. Unfortunately, the last time the NSA director was called before a congressional subcommittee, his statements don't seem to match up with the actual operations of his agency, as they've been leaked since. I hear some congressional reps are pretty mad about that.
The problem with the NSA is that if they are abusing their power, nobody will ever know about it, because everybody they deal with is sworn to secrecy. Abuses are far more likely to happen in this situation, not because of any inherent maliciousness, but because whenever you have a large organization that never has to face an opposing viewpoint you end up with groupthink and a large possibility of ill-considered decisions.
I'd be satisfied with detailed congressional oversight. Unfortunately, the last time the NSA director was called before a congressional subcommittee, his statements don't seem to match up with the actual operations of his agency, as they've been leaked since. I hear some congressional reps are pretty mad about that.