If information naturally wants to be free, then it will necessarily kill anonymity. If it's on the internet (read: information is stored in digital format in some network accessible database) it's simply too easy for it to be copied and spread and revealed. If you want to remain anonymous, stay off the internet. If you want to participate in the internet, you gotta accept that whatever you do, however tightly held to your chest, will eventually leak and be exposed to the rest of the network.
And I don't think that this phenomenon is necessarily a bad thing.