I do it all the time on Facebook.
I initiate very few friend requests and accept all that come my way. If elementary school classmates who would like to catch up after 20+ years contact me, I'm all ears. I spent 6 years with the same cast of 24 characters, so it's pretty easy to recall who is who. But I actually would like to have some sort of interaction with you. No matter how brief or fleeting. My family makes the majority of my FB friend list, so what I would like them to know en masse is obviously different then what I would tell people who I haven't seen in decades. I'm sure eventually there will be somesort of tiered system, with friendship catergories.
In the meantime I'm not an investigative reporter, I don't want to piece your life together from wall posts. And if you don't have the time to tell me what's going on with you that's fine too. Contact me when you have a minute. In the meantime, I'm content to cull my list so that I have some idea as to who knows what about me. This blog might be public, but if a tree falls and no one is there to hear it does it make a sound?
In addition to being the private sort, I'm nosey as all hell so I've delighted in the "where are the now" edition of my life via FB. Years have passed but with a few notable exceptions there haven't been many "wtf happened to _____" moments.
Safe in the knowledge that you did in fact end up a Real Housewife of NJ, an investment banker or an attorney, I wish you all the best. And UnFriend you...