1. That FB split into N independent companies, whereupon each share of FB would become 1 share in each of N companies.

2. That the supermajor shareholders (say, more than 10% of any company) each pick at most one company to retain that interest in, and sell off shares in the other companies until they had less than 10% of each of those).

3. That the new companies avoid overlapping directors.

It would be a long time in court. See the breakup of AT&T.