One option is that companies with sufficiently widespread services can't close your account or block you without due process. And restrict the ability of a ban to spread between services of such a company.

Anti-trust laws, regulation on how to handle criminal activity on their platform (transfer detected pornography cases to law enforcement and allow them to decide what to do with the person and its related accounts. Google should not be handling something like this), and other privacy laws? I don't get why you tried to make this gotcha, this isn't a stretch by any imagination - the auto industry is incredibly regulated in the US and that's working well. Or just look at the privacy laws in the EU.