Well, you see, this is exactly why I would be cautious: I don't know that they would go through those stages. It seems to me that they would be just as likely to freak out at the thought of someone they knew seeing that side of them, flee the site, and never talk to you again.
It's always dangerous to assume that anyone else will react in the way that you would.
Well hey, don't get me wrong, if I felt the person might react that way, or wouldn't want to hear from me in that sense, then I wouldn't contact them. However, two things to consider:
First, I am making the assumption that this person is socially outspoken and active on the forum. That would make it difficult to just avoid them, at least for me as I feel I have to enforce my anonymity strictly enough on here anyway without having to worry about hiding from people I actually know irl.
Secondly, the OP also states that the identity of this person would be "obvious", and as an example he mentions that the individual might have posted pictures. Well, that is the only way to be 100% certain of who they are. So I assume that this hypothetical person, then, is not only socially outspoken, but has also chosen to put him/herself out there with a photo. To me that is very much a conscious decision, and not one that would (or for that matter
should) be made by someone who is nervous about their presence here.
As such, I'd rather just have it all in the open between me and that person, because just leaving it be might end even worse than if I just deal with it right away. Consider my whereabouts for a moment, and the fact that there are not a whole lot of Swedes on this forum. I'm hardly prolific around here, but an active member like that might well notice me even if I just stay away from them but keep posting in threads that interest me, and what then? If they try to interact with me in a thread, that could get all kinds of awkward and weird, not to mention if they choose to PM me... at that point I'd have no choice but to make a reveal, and then at best it would just seem odd that I've known about them all along but not said anything, and at worst, it might come off as a bit creepy. People are very quick to read a bunch of nonsense into your actions regardless of what you do, so as I've said, given my particular, hypothetical version of this scenario, I would prefer to just have it dealt with.