Surely this is more about political coercion than tax? Amongst all US companies that offshore profits, including the likes of Halliburton, Facebook has been singled out because the US administration wants the company to do it's bidding regarding policy and algorithms for political advertising? Especially considering all the other political reprisals and pardons that are in the news, following the impeachment acquitta…
That said, I do believe that tackling offshore revenue is a good move.