Don't get me wrong, it was once in the 5 years I've been doing it it's happened so hardly a major issue, but was somewhat of an eye opener. There are also stories of people having their account locked because PayPal have rejected payments ect. I think the main thing is how much the community features mean to you, in my case, absolutely nothing, so all that's left is a layer of DRM (often extra to other DRM in games like Games for Windows live).
That said, one place Steam as caught my attention of late is the Steam workshop. It really seems to be bringing back the idea of more games being moddable which is something I wholeheartedly support. I miss the good old days where almost all games that came out for the Unreal Engine had an editor packed with it as standard.