I filed a provisional patent app in '96 for a "presence protocol" based decentralized personal networking governed by a social model. I ran into the same precise issue and must sheepishly admit permitted it to get the better of me and abandoned it. Watching the likes of FB, G+ et al these past few years has been a somewhat bitter experience. :)
I guess the silver lining is that I am in possession of government stamped receipt confirming prior art in this domain.
I think this argues rather strongly against patents. After all, if you didn't publish it and someone else came up with it independently several times over then clearly that counts as anecdotal support for ideas having a way of re-surfacing many times until the time is ripe.
The fact that you thought of it first - assuming you did, because there may be many more people like you, some of those may have had the idea even earlier - should not give you a right to a slice of someone else's pie.
Further note I have no interest in taking a slice of anyone's pie. If I did, I would not be discussing this matter here with you; I would have taken my lawyer's advice. The only (hypothetical) interest at this point would have been to defend against a patent in this domain.
I guess the silver lining is that I am in possession of government stamped receipt confirming prior art in this domain.