Well, what else could there be? People behaving better at all times and never doing anything they'll regret being known later?

Sure, removing results from search engines is not a 100% solution (people could still find the stuff from elsewhere, e.g links on a blog or a newssite, if they are so determined).

But it's a working 99% solution. Most people data would be non retrievable and languish into extinction. You don't have to make something impossible to discourage people from doing it. You can just make it a little harder.

Removing your old data from Google, FB etc, is a huge boost in giving one's past a clean slate. Heck, even for murderers there's a "statute of limitations". Why should the "star wars kid" be forever "that idiot you did that when he was 10 years old"?

The dark net, TOR, Diaspora, using services that respect privacy, etc.