According to consolidated financial statements and reports of the Tor Project for the year ending December 2012, US Federal agencies are responsible for nearly sixty percent of funds received by the project. Tor has taken a defensive stand against this, but who knows?
Tor was created by the US Air Force. Surprise, surprise, they still want to fund it. Sooo, why did they create Tor? Well, as it turns out, we've got this massive high speed satellite and ground network we use for military purposes, which basically amounts to a compartmentalized version of the internet. And within that, because soldiers are away from home for months or years at a time, they decided to offer internet access to them. Often they're on board carriers, or deployed in places where a direct hookup isn't really feasible. And they want to make sure that all that traffic isn't pouring out at locations that can be easily monitored... because as much as operational security is drilled into soldiers, loose lips sink ships and all, they're still human. They can screw up.
So they needed some way of giving them internet access without making it pathetically easy for foreign powers to simply tap a couple key routers and see everything any soldier browses (Facebook anyone?)... Enter Tor.
Tor has over 13,000 exit nodes all over the world. And it's expensive to monitor every node. Not only that, but you have no idea where in the Tor network the traffic originated from -- is this J. Random Soldier, or Closet Gay Guy Looking At Porn? Noooobody knows. It wasn't meant to be high security. It's not meant to be totally anonymous; It's meant to make it difficult for small-time players like, say, Iran, to spy on our soldier's personal communications. Because this has happened, and it has killed people; A cell phone left on in a soldier's pocket during an operation led to the death of a half dozen marines when enemy combatants used the signal to figure out when they were leaving base... and they planned an ambush.
So Tor will be funded by our government for the conceivable future, and they have a vested interest in maintaining the security of the network to the point that it would cost an adversary more to 'break' the network than the intelligence value of the soldiers' personal internet browsing.
Does this worry me? Nope. Tin foil hat time? Not a chance. Don't use Tor for high value communications. But then... that goes for the public internet as well. If you want to secure high value communications, you build your own VPN, and then add code to have it transmit/receive at a constant rate to deter traffic analysis. Which, coincidentally, is what most financial institutions these days do.