Facebook taking mobile numbers from other sources and adding them to profiles

Things like this are why I got into the habit of checking Facebook's settings every once in a while. Not that it would help much in this case, but hey. They seem to have a knack for fucking with my settings and reverting them to their respective defaults every now and then.

My pictures or posts are not visible to anyone but who's friends with me. Nobody can post anything on my wall or tag me in any picture or wall post without me approving the tag. Nobody can add me as a friend if they are not also friends with at least one of my friends (and I hate that I can't prevent anyone from adding me, only enabling it when I actually need it or asking for friendship myself).

That being said, Facebook might as well do without asking you if you want to give them your phone number if they end up disregarding your decision and getting it anyway.

That's a dick move that might well mean I will delete my account. Not that it would make any difference for them, but being without Facebook won't make any difference to my life either.

Every so often FB asks me to add my mobile number and pre-fills the field with some number I'm not familiar with. Not mine, nor anyone I know. Perhaps I should celebrate. ;)

(I haven't paid attention to whether it's the same number every time I've been asked, though; I probably should, and perhaps do a reverse search on it to see if I can find out who it belongs to.)

Currently you need a mobile number to create a FB account. For older profiles (I created mine back in 2007), it was not necessary, and I will not provide it to FB anyway.