How is posting an address and phone number on FB any different than having it listed in the white pages?
It's odd, when I discovered forums on the internet, I wondered why people used made up names. Someone said it was for security. But on FB, everybody uses their real names. I don't twitter or any other ones but I suspect it's the same there.
Mayybe what multiplies the danger, is that our name and address are coupled with lots of other personal information on FB. One thing nice on FB though is that I can decide who I want to read/see my information, everybody, friends, or friends of friends.