OK, just for the sake of argument, let's assume the FBI (with the help of the NSA friends, or otherwise) have "broken" Tor in some sense. Whether it's by controlling enough nodes to do traffic analysis, or a fundamental flaw in the software, or a backdoor or whatever.

Given that, if you were going to run a SR like site, are any of the other anonymizing networks of various sorts (Freenet, I2P, whatever) a valid alternative? And would any of those deals be better than Tor in any meaningful way?