Preserving anonymity on Facebook

Hi - new to the forum. I just found it via a Google search for "internet privacy forum" so I hope this post is appropriate.

I have never been a member of Facebook, mainly because I've never had any reason to join, but also because I dislike its business model and the way it extracts information from members.

This has caused me no problems until recently, when I got involved with the running of a local community centre. Unbeknownst to me, it seemed that a lot of the discussion about the centre was taking place on Facebook and I was "out of the loop". Some people put a certain amount of pressure on me to join, but I refused. I was responsible for maintaining the centre's website and ensured that all relevant information was posted there rather than being confined to Facebook. However, it was still useful for me to know what had been posted to the centre's Facebook page, to avoid too much duplication.

At first I could read the Facebook page easily as a non-member, but then they started putting banners up that made it difficult for me to read it unless I joined. I put up with this for a while, but eventually decided to create a dummy account under a false name purely for the purposes of reading the page. I provided no personal information whatsoever beyond my actual date of birth and mobile phone number (both of which were required as I recall).

Then, purely out of curiosity one day, I looked to see what "friends" had been recommended for me. Most of them were people I'd never heard of in other parts of the world, but to my surprise a considerable number of familiar names popped up. They were mostly other users of the community centre, and I reasoned that because I frequently visited that page, the software had inferred that I might know them.

But then I had a bigger shock. The name came up of someone who I used to be on a course with and still occasionally maintain contact with. She had no connection to the community centre. Then it came up with the name of someone I used to drink with occasionally and haven't seen for years. It was starting to freak me out. I hadn't given my real name, location, interests or anything else.

How is Facebook getting hold of this information and should I be concerned about it? If the state were doing this it would doubtless be seen as a "Big Brother" operation, but somehow no one seems to object if a large, powerful commercial corporation is doing the same thing.

I should add that I am no longer involved with the community centre and no longer use the Facebook login, though I haven't deleted it.

Posted to another forum about this and it seems as though I've got the answer. I don't have a smartphone, but it looks as though Facebook has found my phone number in the lists of contacts of other people I know who have chosen to share those contacts with Facebook (or possibly Facebook has taken the details without permission). Whichever way round it is, I regard it as an infringement of privacy. I do not give out my contact details to people for them to be shared with giant corporations.