I would not trust Tor (by itself) to hide from the Government but I would trust it if I wanted to hide my IP address from a particular website, for example.
If all you're concerned with is keeping basic information out of the hands of comparatively low-resource adversaries (such as hiding your IP address from single website and its authors/owners) there are low-cost and comparatively simple solutions. For examples, a decent VPN or visit to Starbucks costs <$10. (And there are also free proxies, within limits.)
I thought the whole point of Tor was that it would work against highly capable or motivated adversaries?
I'm just saying that if I was trying to hide data from the government, I would be much more paranoid (in some cases it might be a good idea to use a device not owned by you on somebody's else network, for example)... but in cases where you are facing a low-resource adversary, I would not bother with a non-free VPN when you can have Tor for free which have the potential to be better then a VPN.
Surely, if you're paranoid about hiding data from the government, it should be easy enough to handle by using a secondhand diskless laptop with a USB live distro with no RW filesystem, and then wardriving for people running WEP or WPS on their wifis? Especially WPS is still common and can be cracked quite quickly. With one of those big-patch-antenna USB wifi cards that go for $40 on ebay, you can use an AP from several hundred yards easily.
Why not just point that big patch at a busy coffee shop? There are lots of open wifi spots out there.
Honestly, if you are doing things so naughty (which I don't advocate) that you are worried about state adversaries using lots of resources to track you down, you probably need a level of OpSec that you are not likely to achieve without being supported by another state level espionage agency. But at the very least you should be disguising yourself (in such a way that you still blend in), you should not be accessing an AP within a few hundred miles of where you actually live, you should probably not be driving your personal vehicle anywhere near the AP you log into (instead, using public transport paid with cash and then sitting on a park bench near the AP), you should probably be using a computer you purchased second hand from a thrift store with cash at least 6 months ago, you should probably wear gloves, you should probably dispose of the computer in a public dumpster in a different town than you accessed the AP. Hell, you probably shouldn't even download TAILS from an IP you control, I have no doubt every Tor Bundle and TAILS and WHONIX download is logged for cross referencing. Even with all of that, I honestly doubt that in the current climate a normal, highly careful person could remain anonymous if they were targeted by a major western intelligence agency like the NSA or the GCHQ.
I think you're right about the extreme level of opsec required, but with that level of opsec I think it would be feasible to avoid being targeted by the intelligence agency in the first place. Which is the key to survival.
Obviously this means you are doing something illegal but undetected, like spying for the Russians or Chinese in the West, spying for the West in Russia or China, etc.
OTOH, if you are doing something like exposing human rights violations in China/Russia/Iran/etc. where, by its very nature, the results of your (in that place) illegal activity are published, you are far more likely to be targeted.
> diskless laptop with a USB live distro with no RW filesystem
Which distro? One known problem is that browsers still transmit their location. If the network and the laptop are hundreds of yards distant, that's an instant red flag. Once that problem is corrected, there may be unknown problems to deal with.
TAILS. And unless you are using GPS, which would be a silly thing to do on a device you were using to achieve maximum anonymity, your laptop has no idea precisely where you are.
