the tinfoil take is that everyone in charge is fully aware of this eventual problem such that when it occurs, a solution will be presented: ubiquitous verifiable digital ID technology that's required to use popular social media services, such that everything that a Real Person posts will be signed with said digital ID, thus bringing about the end of online anonymity, and the death of the Internet as we presently know it.
idk, sounds plausible to me, the way things've been going.