Well, this is odd. I was going through my LinkedIn account today and had the name of a provider I saw a few times several years ago pop up. I know it's her because the e-mail address that came up with the name was very similar to one she used when I was seeing her. In one of those oops-I-didn't-mean-to-click-on-that moments, I clicked on the "invite" button. After I clicked on the link, the little box with her name in it went away, and I can't find her again. (I'll confess to not be terribly proficient at navigating LinkedIn yet.)
Since I can't locate her, I can't figure out how she popped up. I'm reasonably sure that I never gave her my last name, and I'm pretty sure we don't have any shared employers in our respective pasts.
The only thing I can think of is that someone I'm already linked to knows her in a non-hobby capacity.
I'm not as concerned about discretion as I might be with some other ladies, but I do find it interesting, and perhaps worthy of discussion from those of you who know social media better than I.