Its protection schemes are horrible, its customer service even worse. Had several episodes where it wouldnt allow me to reopen my account on a new system or after reinstalling Windblows and then would only get automated responses to my requests. Steam sucks but Halflife2 is great go figure. Ill make do with Mac gaming as long as we get things like BioShock, ETQW, Flatout2 etc etc. Steam will Steam you sooner or later.
How very odd. I've been a user since its beta days (my original account was back when they used email addresses for logging in) and I've never had that problem. I run my account off 3 computers at home (off a portable drive) and I used to use my girlfriends computer when she was at university... never had a problem logging in.
The protection scheme isn't horrible at all. If you haven't disabled offline mode it doesn't even exist, you just can't move the account to another computer until it goes online again.