If you're of extreme interest to the US government or any of its allies, you must also assume
4) The authorities can read any of your encrypted data, if they find out it is associated with you, even if they do not acquire the keys.
If you assume encryption is useless, then what's the point? I would think that if you generate the key yourself and no one else knows/has it, then encrypted data is safe (assuming you are using a modern cryptosystem).
Not only is UNIX dead, it's starting to smell really bad. -- Rob Pike