I'm sorry that happened. I've never seen stuff like this but this is likely because I disable as much shit as I can every time I set Firefox up on a new system. As you can see from the list of recs I linked above, it's a bit of a chore.

There are definitely smarter ways to go about it, like scripting the disablement of stupid shit in Firefox (or using a privacy respecting fork of the browser), but I like to do this / monitor this manually to keep track of any newly introduced anti features.