Steam installed as root (Score 1)

The thing that puts me off using Steam under Linux is that I have to install it as root. I only use Windows (XP) for games. One of the endearing features of windows is that it's useless at interfacing with other file systems. My assumption is that if Steam develops a security hole, gets hacked and starts trampling across my system from a Windows install, it's not going to be able to do any subtle damage to my Linux disks containing my life. From a Linux install it already has access to the entire system.