They're pretty brief:
The most important rule: Don't be a jerk. We want our messageboards to be a fun and friendly place.
Users who participate in our message boards agree to not: post any content that infringes and/or violates any patent, trademark, copyright, or other proprietary right of any third party; use profanity or any type of vulgar speech; make any bigoted, hateful or racially offensive statements; defame, abuse, stalk, harass or threaten others; advocate illegal activity or discuss illegal activities with the intent to commit them.
There are some interpretations people sometimes get surprised by - posts discussing ways that pirates circumvent IP are usually deleted under the "advocate illegal activities" rule (resulting in some pretty vociferous objections). No doubt allowing an academic discussion of such would be a pretty obvious loophole.
They also generally delete both objectionable posts and posts replying to or stemming from those. So you'll sometimes get 'caught in the crossfire' so to speak.