Oh I'm sure that's the case for nearly all large social media and network systems based on the US. I'm also willing to bet that for some of these companies, almost no one even knows it's there, either because a 3 letter agency put it there themselves without being noticed, or an employee implemented it for them without corporate approval.

The US is worried about other countries doing this because we 100% are doing it ourselves. From a national security perspective, it's basically common sense. Ensure you have access to everything, even if you don't use it now, you might in the future and it will save time.