OP means they aren't in and of themselves a problem if the citizens do their job and hold their democratic government accountable and force it to abide by their collective decisions.
I don't agree, though; I think secret surveillance is in and of itself anti-democratic. However, OP is correct too, in the sense that once it is revealed that secret, illegal surveillance is going on, if the subjects of a functioning democracy don't care or take any action, that is probably even more corrosive to a democratic state (since presumably there will eventually always be people like Norden^W Snowden, and nothing stays secret forever).
I don't agree, though; I think secret surveillance is in and of itself anti-democratic. However, OP is correct too, in the sense that once it is revealed that secret, illegal surveillance is going on, if the subjects of a functioning democracy don't care or take any action, that is probably even more corrosive to a democratic state (since presumably there will eventually always be people like Norden^W Snowden, and nothing stays secret forever).