This latest identified threat by Futuremark [by someone posting on Futuremark's site]* is one that relates to a driver being installed on your computer that gains RING0 access (the highest level of access to your computer). The installation requires Administrator level access to install the driver, which runs all of the time regardless of whether or not you're playing a game with Starforce DRM.
With such a high level of processor access (sharing the same levels the operating system enjoys), the Starforce driver can do anything to your computer at any time. This very ability is demonstrated, since the Starforce driver will force a reboot (not a shutdown) when it thinks it has discovered suspicious activity related to copying. The reboot occurs instantly, and any and all unsaved data could be lost.
Some in the gaming community have urged a boycott of Starforce protected games. Remains to be seen whether this will be an effective tactic.