To mitigate this, the non-shitty network should require a verified phone number. This is far from a complete solution, but most people have one and only one phone number.
Eventually, authorities could be established who vet the real identity of a user, and provide an additional badge of authenticity. (aka Twitters "blue chekmark")
It is generally a good idea to keep a rating for every user, so that content produced by assholes can be hidden.