Before land lines had gone away, when I lived in Atlanta.

I have a very common name, and collections agencies would buy debt and try to collect by 'Sarah Connor-ing' their way through the phone book calling everyone with my name. I'm not the aerocontrols who didn't pay off his plasma TV at Best Buy, but the only way to prove that was to give them the last 4 of my social. (The worst part was that they socially-engineered me into calling THEM back by leaving vague, ominous-sounding messages on my answering machine)

Eventually I got sick of it and told some lady I wouldn't give her my last 4, which set her off and convinced her I was the aerocontrols who owed the debt! She called again and again, but now it was fun, because it was on my terms, and I was driving her crazy. Finally I moved and got a cell phone and the collections agencies' business model broke because nobody is listed anymore.