I think they use something like namecoin to store usernames and public keys,and laso increasing the number of registered users from 20 millin in namecoin which

I think they use something like namecoin to store usernames and public keys,and laso increasing the number of registered users from 20 millin in namecoin which is quite limited, and combine it with a distributed dB for message storage and anonymous networking. Also adding advertising as paymemt for security is smart and I could see it enabling companies in that area.