From Software don't much like gamers. They don't want you enjoying yourself when you play their game - unless sadistic difficulty levels appeal to you - they don't much care for well-implemented mechanics - again, unless you're a fan of their particular design philosophies - and now it appears they're out to punish Dark Souls customers who jump the line and grab a an early copy of the game in illicit fashion.
So, you've picked up a copy of Dark Souls early - maybe you nabbed it off a shipment boat or mugged a From Software rep - and you've settled down at home for a good old session. Well, you're in for a cruel surprise. In Dark Souls, players can join any other players' sessions on the fly, invading their game to help or hinder.
Beginning to get an idea? Yes, if you fire up an early copy of Dark Souls, max-level Black Phantoms will enter your game and tear you to shreds. It'll likely take you a hundred hours just to match their stats alone, which simply can't be accomplished without the use of a time-machine. And I think they've all been booked. [Esuteru]