Like any other software Tor has problems. Just look through their changelog. Tor has had plenty of issues. But on the whole it's very good.
Remember the "Tor Stinks" slide from the Snowden leaks? The NSA, with direct taps on the internet backbone, has had lots of trouble deanonymizing Tor users.
I would assume that the NSA no longer has difficulty deanonymizing tor users, mostly from their own sloppiness. For a sufficiently paranoid net user, they will already have other mitigating factors in place. No phone, no cctv, laptop booted from solid state media, all EEPROMs on motherboard in read only mode, etc.
Oh I agree with that. Targetted versus en masse surveillance, though, as the cost of personnel and equipment would have to scale with the number of targets to deanonymize.
Everyone's data gets sucked up as the default, but with Tor - I think they Snowden docs showed they could only get about 1/4 with automation. I do not remember the exact percentage.
The combination of CALEA, Stored Communications Act, and Patriot Act under the Third Party Doctrine mean the system stores and processes our data by default, over a sliding window. (IIRC there were some Snowden programs that had windows of around 5 years?)
With Tor you increase the cost to taxpayers a little and decrease the chances (especially with good cyber hygiene) that you'll give everything. If you use a cell phone you give your exact time and place 24/7. Even local police have access to these cell phone tracking databases. You can't Tor a cell phone.
Tor isn't really a good answer to the system. But if you need privacy, there's a corner in Tor.
I totally agree that more people should tunnel traffic over Tor, it only helps everyone the more people that use Tor. If one person used Tor, it would suck. :)
Remember the "Tor Stinks" slide from the Snowden leaks? The NSA, with direct taps on the internet backbone, has had lots of trouble deanonymizing Tor users.