Deleting or not deleting, I dunno.
I started talking on the internet when I was 9. I've always had to live with the paranoia of my data following me around everywhere. Because it does, it could exist somewhere, even if I delete it. Who sees it? The people that matter (other technology folks, since that's where I've directed my career towards), or the rest of the world?
At the end of the day, my feelings are this. Everyone has issues. Everyone looks brilliant sometimes, and dumb other times. Everyone makes mistakes, some are better at hiding them than others, but that doesn't mean anyone is perfect.
It's easier to just not judge. Don't let others past drag behind them, don't use their past against them. Because, it's a mental prison you either force yourself in, or force others in. The way you treat the world either is the way you see the world, or it becomes the way you see the world.
Also, all those mistakes can add up to something great. Error seeking mentality can turn into error prone mentality. It's important to have tolerance for yourself, and others.
This is the direction everything went in. Collect as much data as possible. Inferences can be blinding. Of course it's going to affect people.