In Facebook's case they own some of their biggest potential competitors for attention and deliberately preserve their niches. So splitting them up might make a difference. But if not, requiring an open network akin to the telephone system with standardized protocols might make a difference.
AT&T was split on geographical lines, so maybe FB could be as well, and the regionals would all have to interoperate with open protocols that would allow for regional competitors.
AT&T was split on geographical lines, so maybe FB could be as well, and the regionals would all have to interoperate with open protocols that would allow for regional competitors.