Well, some people consider the FISA courts to be meaningful restraints. Certainly legal restraint. I mean according to those federal judges, anyway. And near blanket coverage is simply not true, period. Unless you have a very liberal definition of "near".
You mean the secret court that issues secret orders? Yeah, sure, I am satisfied with that restraint, especially since in this courtroom there is no advocate present except the government wanting information.
And "near blanket" is obviously a loose term, but what we do know is the information gathered is indiscriminate. It's how they can do three hop analyses off a suspect. So if a journalist calls a contact in the Afghanistan government, and that contact calls his third cousin, who has a son working for a charity that five years later becomes a suspect in an investigation, all the journalist's records are fair game, and that's if they go by the rules. And of course, they have to have had all those records to search, going back years, which they DO have. Obviously, any journalist doing investigative work, or any activist or protester or other person doing anything the government doesn't like much, likely falls into dozens of three hop analyses, and so can have their records legally examined.
Do you wonder why, of the 40,000+ folks who work at NSA, the vast, vast majority of them have no problem with what it does? They who know much more of it than normal folks? Is it because they're all bad people? Dumb? Or could it be something else?
What strikes me there is the casual reference to 40,000 individuals at NSA, with a mostly black budget doing stuff no one knows about..... FORTY THOUSAND employees! And that surely doesn't include at least 10s of thousands of other employees at private companies doing NSA work. That's a whole lot of folks doing work we can't know anything about...
But as to your question, I have no doubt almost all of the employees think they're doing, and ARE doing, important work for the benefit of the U.S. But that's irrelevant because if that information is gathered about YOU, and you're a political opponent of the current administration, or an activist, or a protester, or a whistle blower, then it's a database query to get all YOUR records, and all you can do is 'trust' the government not to abuse the powers we gave them. Sorry, but if you're working against, say, a corrupt government and then trusting that corrupt government to not use information it has gathered on you, you're not thinking about this very clearly.