Earlier quoted context omitted.
In the UK, Parliament is sovereign. FB had repeatedly refused to appear before a parliamentary committee to give evidence in the Cambridge Analytica case. Now, I'm not totally certain of the precise legal position, but because of its sovereignty, Parliament can act in a quasi-judicial way, so in effect, FB's actions can be seen as roughly equivalent to refusing a subpoena. FB's refusal authorised Parliament to seize…
You are basically normalizing violent response to a non-violent action. US can do that because FB is US company. UK cannot just because you happen to visit. Please realize that other states are taking notes at this situation. They are waiting for US/UK/etc exec to visit and make the same excuse.
Other states aren't waiting for this at all; least of all the US. In the past when UK based executives of online gambling firms have travelled in transit via the US they have been arrested even before going through customs, in effect in international law it is somewhat akin to piracy, USG sanctioned piracy. This sort of creative use of laws to acquire information and/or people by various governments world wide has been happening for a very very long time.