http://store.steampowered.com/subscriber_agreement/ Clause 12
Why this is evil:
Arbitration is often a kangaroo court, where companies win 99% of the time because the arbitrator's employment is determined by the company they are arbitrating. This is something I would actually think hard about boycotting Stardock over. Valve, I trust them less, and I'm uninstalling Steam over this.
I'll probably re-install at some point, but there are enough alternatives to Steam out there still that I can get by for some time.
This is why Stardock needs to stay away from mandatory Steamworks.