Meta also has offices and thousands of employees in the UK. Presumably the UK government could ban them from operating in the UK completely which would be a pretty big hit to those employees and all the teams that are based there.
I would hope they wouldn't do that to their own people. You're not really hurting FB, you're hurting your own citizens.
Is that really the best use of regulation, political power, etc?
Can FB buy Tenor then? Is any gif service off limits?
Who can buy Giphy? Any other social media?