Constant net connection required to play Assassin's Creed 2 on PC
 

We've just received Assassin's Creed 2 and Settlers VII for review, and verified with Ubisoft that the DRM is the same as the boxed product. If you get disconnected while playing, you're booted out of the game. All your progress since the last checkpoint or savegame is lost, and your only options are to quit to Windows or wait until you're reconnected.

http://www.computerandvideogames.com...35290&site=pcg

Oh c'mon, this is absolutely lame. And it won't surprise me if this anti-piracy measurement is bypassed after a few months.
Every person with a bit of common sense knows that 'dropping you out of the game and discarding all your progess' is a ginormous reason NOT to buy the game (and just waiting for a cracked version that doesn't get you frustrated).

Probably will be bypassed in days.

It is possible to play any Steam game without an account, online, even on secured servers without detection, and I'd consider Steam's setup to be more secure than most.