Also what actual benefits would a "decentralized" social network bring? Facebook works because it got a lot of things right it let people communicate and share ideas rather than being a glorified geocities where bands come to die like MySpace and it got a critical mass of users which drove it home.
Blockchain will not decentralize the internet it might decentralize the World Wide Web, but even then considering the power costs and the fact that bandwidth still costs a ton of money even in developed nations why would you want to "decentralize" a bandwidth rich service in the current landscape.
I can understand the usefulness of a blockchain for certain applications e.g. clearing houses. But every time some one says it's like X but decentralized and runs on the hot new blockchain I just want to head bang a wall, I could be too old or too dumb to get my head around it but it simply looks to me that there is a cool toy that every one wants to use as a hammer which makes them look at everything that they want to build as a nail regardless if it makes sense or not.