Grit, I personally have connected with some people thru FB early on in my sitch. It occurred early on in my heavy FB usage as well. As I started to connect with real world friends; I became sketchy on who I communicated with from DB, for all the same reasons that you and Lola have stated. When I started on FB and DB, my W was NOT a friend of mine on FB. Now she is and since we are processing our D, I refrain from commentary on my marriage totally on FB.
There are a few people that I still keep in contact with on FB and they no longer post here. The majority of the those that I "friended" sit in the background of my online world.
I don't necessarily think it's a bad idea to connect on FB; but you have to treat it the same as how you would connect with people in real life. Let's just say if we were all sitting in a support group and had just met each other; how comfortable would we be giving up our personal info in that situation?
Back when I started here at DB, this forum was moderated pretty heavily and it was difficult to get in touch with DB'ers on FB. The policy in place preventing PMs and exchange of personal information is in place to protect individuals in this very vulnerable period. Plus, there are predators who may come on here to exploit that pain and vulnerability. and MWD doesn't want this to become a dating site!!
on a different note, some people create alternate ID's for FB so that they can separate their real life from their DB life.
I have de-friended a couple of people...mostly because we don't really know each other anyway. Over time, as I heal; I'll probably drop most of my DB friends, save about 3 of them that I have come to really like.
So my opinion, is that FB and DB is a mixed bag. Treat your virtual relationships the same as you would your real life relationships.