Although I do agree that is has become harder to start anew without your past catching up with you, in my experience of growing up in a small community, if you did something bad or just had a bad name, people would learn about it two towns over when you would start dating someone there, or trying to get a job, or moving there. The "social network" might seem all revolutionary, but what has changed most is the scale of the network, both in nodes, geographical spread, and memory, not the social aspect as such.

However, where we could escape the confines of the small-town community by moving to the city or even further away, nowadays even moving to the other side of the world isn't going to help much any more unless you find someplace off the grid. It is something to worry about.

Maybe changing your name might work, though, as long as Internet search engines aren't smart enough to connect your new name to your old one that's plastered all over the Internet.