I am not a member of Facebook and have no intention of joining, but get fairly regular requests from friends, via Facebook, to do so. What horrifies me is the "Other people you may know on Facebook:", some of whom I know well, some of whom I am not friends with but had very brief contact with professionally years ago, and some I don't know at all. I have several different emails, so requests sent to different email addresses bring different "friends". I can only come to the conclusion that all these suggested friends must be members and have somehow uploaded my email address to their Facebook account. When you join Facebook, does it automatically search the address book on your computer? Call me paranoid if you like, but I really don't like this.
As with you, I am NOT and never will be a member of Facebook or the like. Still I do have a few friends and acquaintances who are members. When they initially joined (the club's) I would get requests from the said clubs to join myself. Following this, from time to time I get emails, from people I've never heard of wanting to be my friend.
I think you are probably correct, in your first assumption. That the 'friend's' in question have indeed uploaded your/our email address.
If you are getting too many messages and don't like your address being out there, may I suggest you contact your known to be member 'friends' and ask them if this is indeed the case and if it is? If they wouldn't mind - in the name of real friendship - removing your email address from Facebook or wherever.
In my case I just tell my 'Junk Email Filter' that I don't want anything from the said companies. So now I don't get them any more.
It does not automatically go through your email list it asks if you want to and if you do it then asks for your email password (which it does not keep) so if it has done then your friends must have made a point of doing it.
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