I found it a source of pain until I stopped all the notification emails.

I will go out on a limb and say your situation is not unique - there will be others that have had a similar experience, but that's not to say I'm not sympathetic - that's a proper shitty thing to happen to anyone.

I do believe however, that it's made contacting people from your past much easier, and because Facebook doesn't have the stigma of a dating site attached to it, it is more socially acceptable place to 'meet people' through it. I'd also go out on my other limb and say that if something like that is going to happen, it will - at the end of the day, you can't control who people speak to, and the same as anything in life, if you don't know something's going on, there's not much you can do to fix or work around it.

I deliberately avoided adding someone from my past to avoid the potential grief of a similar situation to yours, I think I did the right thing, but everybody's different.