Opera browser isn't open sourced, yet you recommended it earlier. Now, I use Opera, and have for many years now (through v12 anyway, I won't touch the new v15+), but your argument is bordering on paranoid. Don't get me wrong, I'm all for paranoia-based security. I practice it, and recommend it to my customers, but calling Steam a security risk because it's closed source is a bit over the top.
And as for the DRM aspect, when a game with Steam DRM implemented runs, all it does is check to make sure Steam is running and that you're authorized to run it. Hardly a security fear. Other DRM solutions, such as Starforce and even SecuROM, are much more dangerous, as they can run with Ring-0 access to your system. Steam DRM isn't even close to that level of danger.
