The only thing that's going to stop this is them being forced - legally - to actually respect the citizens of this country again, and that's not going to happen until this gets coverage outside of tech sites, and the general public actually starts to care again. It's the same crap that happened with McCarthyism, just with more modern technology driving it. The other key difference though is that in the 60s, there were ENORMOUS protests and activist movements, and the government was forced to listen to the people. Here, we've got plenty of website coverage and people writing posts about it, but no real organized protests, and virtually no attention being paid at all to this outside of the internet. That needs to change, but the problem of course, is figuring out how to change it. What finally got the people to care last time was the huge body count in Vietnam, and there's nothing like that this time around.
The "overload the system with crap" approach SOUNDS great, and HAS been tried before, but with limited success. The 2600 guys tried to crash Carnivore (one of the older systems for this) by chain forwarding an email with a huge pile of flag words in it. I THINK it actually worked, but sadly, they've improved their code since then so that won't work in the future - or at least that exact approach. Of course, the activists can then improve their algorithm so it's less obviously fake, forcing the NSA to improve theirs, and so on. The result is an arms race of competing code. The problem is that the people trying to stop this are a small group of activist hackers working in their spare time, while the NSA making the system has a multibillion dollar programming team. There's also the obvious problem that building a system that's knowingly designed to interfere with this is - to say the least - rather questionable legally. Normally this wouldn't be a problem - every activist movement has those few willing to go to jail for a few years to stand up for what they believe in. The problem here is that the general public doesn't understand the concept of an activist hacker, and they aren't going to see an activist getting locked up for defending civil rights. They're going to see a "dangerous criminal" being caught for "the good of society", and actually believe that.