The problem with the NSA is we have no idea what their capabilities are, technologically or legally.
Well, if you read all NSA-related legislation, you should have a good idea of their LEGAL capabilities are.
Which, unfortunately means reading basically ALL legislation passed since NSA was founded, since a rider could have been inserted into unrelated legislation quite easily.
They are clearly violating the constitution already and there seems to be no one willing or capable of stopping them.
There are several people CAPABLE of stopping them. The President, for one, being their boss. Congress can always just defund them.
Alas, neither the President nor Congress seems to be WILLING to stop them. Consider this carefully next time you pick a President/Senator/Congressman.
Oh, and try not to fall for the "hope and change" line again. It wasn't true when Obama said it, nor when Bush used his equivalent, nor when Clinton used his variation, nor when Reagan said words to that effect, nor when Nixon said it, nor when Johnson said it, nor Kennedy, nor....
ALL Presidential candidates (except the guys who were former VPs, who usually use a "we'll continue the hope and change of the last eight years") use a variation on that theme. ALL of them are lying.