Do you have evidence for that? Are the security services also the ones that make copies of Stack Overflow content?

Cant say about the Stack Overflow content, I've had loads of webpages removed from from the Wayback Machine.

The idea that everything that goes online stays online forever, forget that, they wipe what they like, so then it means that you get classed as mentally unwell, get locked up without trial and drugs forced down your neck. Rinse and Repeat.

I understand why massacres occur now.

Do you have an example URL that got removed from the wayback machine? I could email them and ask why. I know people sometimes they get DMCA requests which cause them to remove pages, and I think if the robots.txt tells them to remove the whole site, they'll remove all pages from the whole site. I think it's a bit strange to say that a page on the wayback machine being removed leads to drugs being forced down your neck.