Those are big reasons why I have nothing to do with Facebook, texting, and such things: there are people in my past I'd just as soon not hear from, and there are people in my present I want to be sure stay at arms length.
Which is why I started a FB under a pseudonym recently. I ended up not using my 'real' one as I had exes, old school friends and members of my family I don't much like on there and it made me horribly self-conscious. I also got requests from people I know professionally which kinda freaked me out since I like to keep my personal and my professional life separate. On the new one I only have my sisters, close friends and people in the "vintage" community and I can be as corny as I want.
I never got unwanted attention online actually, unless you count people pestering me to crit their fiction, which I don't. But if I did, they'd likely never contact me again, as I'm very harsh.