one thing that sucks about drm with some games, is when they TACK ON 3 drms at the same time! You would think 1 is enough. Thats about the only way you can play PC games now a days is with DRM only :( , since people pirate so much hence why.
Steam, in it's default setup is a HUGE security risk. It leaves a permanent, always on hole where any hacker could push a keystroke logger or virus onto your computer and then take it over. There are ways to lock it down to make it better, and ALWAYS keep in in offline mode unless absolutely necessary. But it is still an unnecessary risk.