Even if they were three separate companies wouldn't Mark still have voting control of all three companies?

I think divestiture would mean a full spin-off to an independent entity.

Generally no, he couldn't do that, as that would be the opposite of the concept of divestment.

I don't think so? Can anyone answer this definitively?

The FTC could, potentially, require:

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.

And then it would eventually come back together. See ATT.

https://money.cnn.com/infographic/technology/att-merger-hist...

"And then it would eventually come back together." That would be hilarious.

But are there not multiple phone companies now instead of just one?

They have all pretty much merged back into AT&T or Verizon. Those two companies together would be the original MA Bell.

And Centurylink.

Duopolies are bad, but I'd say still better than monopolies.

Yes, it was just a possibly funny observation that most of the entities created from the monopoly ended up back in an entity called ATT.

Reminds me of Terminator 2.

Even better, Standard Oil.

Is this not itself an antitrust issue? If so, why?

I am unclear why he would be panicking.

Best case: there's a lot of legal kerfuffle and he is a multi-billionaire

Worst case: there's a lot of legal kerfuffle and he is a multi-billionaire