Helping people with computers... one answer at a time.
Facebook invitations often include suggestions of other people you might know. I'll look at where they might come from, and whether there's a concern.
I have occasionally received 'invitations' from people most of whom I know only vaguely, to join them on Facebook. I've no wish to join Facebook, so just ignore these. Yesterday, however, I received yet another invitation, from someone who runs art classes I once enquired about. Underneath, Facebook lists three other people who have invited me in the past. And, below that, there is a list of nine other people 'whom you may know' - none of whom have ever invited me, and three of whom I have had only very basic contact with - eg a single enquiry made to an archivist.
This really worries me - how do Facebook know that I have ever had any contact with these people? Can Facebook access their emails, see where they are all going to, and cross-reference them with people who have received an invitation from elsewhere? Or can they, having once been given my email address, somehow gain access to my sent messages, see where they are being sent to, and cross-reference them against their existing Facebook membership??
This really worries me - it just seems such an invasion of my privacy, and concerns me that they may be able to access all sorts of personal information and conversations.
Can you explain how this can be happening, and suggest any way to block it, please??
I'm not privy to all the details of how Facebook actually works. That being said, I can hazard a guess as to how Facebook (or any social network with similar capabilities) might be making these recommendations.
No, Facebook's not looking at anyone's email, outside of whatever messages might be getting sent on Facebook itself.
They're making what I'd best characterize as "an educated guess".
First let me say that I'm not at all concerned, and I don't think you need to be either.
Here's what I think happens:
Your friend "Tom" sends you a friend request, which of course you ignore. However, Facebook remembers this.
Another friend "Dick" also sends you a friend request, which again, you ignore. Once again, Facebook remembers.
"Tom" and "Dick" have a friend in common - I'll call him "Harry". Both Tom and Dick invited Harry to be friends, and Harry accepted.
So, here's what Facebook now knows:
Tom claims to know you.
Dick claims to know you.
Tom and Dick both know Harry.
The "educated guess" is simply this: since Tom and Dick both claim to know you and Harry, perhaps you know Harry. Hence Harry becomes an "other person you might know".
And you might. Or you might not.
I find that about 50% of Facebook's initial recommendations are people I don't know, and about half of the remainder are people I might know, but that I don't want to connect with anyway.
Now, as I said, I don't know that this is exactly how Facebook - or any social network - actually works. In fact, I'd be willing to bet that the details are significantly more complex. If nothing else they have millions and millions of relationships in their databases that they can use to make these inferences.
But I'm willing to bet that it's just that: nothing more than Facebook analyzing all the data that its members have provided in the form of friend requests, which groups they've joined, what fan pages they're fans of and more that allow Facebook to infer who might know who - even for people that are not yet members.
I get that it might seem a little creepy, but it's not as intrusive as you fear. It's simply using the social relationships that its members have provided to make a few guesses.
To answer your last question, I'm not aware of a way to block it.