Nobody said he 'stores' the private key. I don't think he has stored these in some giant database. That would be stupid. All I said is he published my key. And he did. And he published your key too. You just don't know which page it is on. But I assure you, your key is there. And everyone else's key is there also.
You know that based on what? Why would anyone generate all that keys and not transfer the bitcoins to their own addresses? How many people have reported getting their bitcoins transferred to some unknown address out of nowhere? How could bitcoin still exist 2 years after that site went up if people can easily find any private key using it?
And no, my private key is not there. Want to prove me wrong? Post it. My address is in my profile
and store in a site .... sounds a bit stranger to me 
if your private key is published in that's site... it's dangerous.