This is silly on a "behind 7 proxies" level. Just go the library. If you're worried that investigators are going to swoop down CSI style to track you down because of your important secrets, maybe you should speak to a psychiatrist.
On the flip side, if you are already are under suspicion, then all your efforts to anonymize a leak are in vain. You'll be the first person interrogated after a leak, and if your beliefs about the Orwellian nature of the government are true, the $10 hammer to the kneecaps (thanks XKCD) will undo any clever hiding you did.
I just don't think it makes much sense to go to these lengths. It's already understood that governments are corrupt. Are the specifics of what secrets you want to publicize worth the personal risk? If no, then you're playing spy, which is fine. If yes, then they'll probably find you if they really put their heart into it.