At nothing resembling the rates of PC games. First, to pirate games on a console, you must
physically modify your console. Welding a pirate chip onto the board is necessary for XBox or Playstation mods. Purchasing a physically altered console or modifying your console by hand is quite a barrier to entry as compared to installing Daemon Tools and knowing where to find torrents (
www.google.com).
Second, there are constant updates of firmware with new games. So if you purchase a game, it tends to update the pirate firmware, occasionally 'bricking' the illegal console. So you are forced to wait for the hacked version.
Third, online play is impossible with a hacked console. Will not happen. Both the XBox and the PS3 have games with large online components.
Piracy on a console is an ignorable joke compared to piracy on a computer. It is not a matter of downloading a few programs, it's a matter of buying a chip and getting a soldering iron. If you just try to burn a DVD and stick it in your console, well... heh. Good luck. You can't copy the disks, and that's that.
The hacked versions of Halo 3 from the dev thing bricked a few hundred consoles and in general saw almost no distribution. The hacked version of Assassin's Creed for the Computer had 700,000 downloads
before the game was released. It's millions now.