I'm actually not coming up with any- it seems to be a tough problem. Here's an elaborate hypothetical that I'm not particularly worried about, but which serves as a case study:

Suppose that Robin Hanson is right about the Singularity (no discontinuity, no singleton, just rapid economic doubling until technology reaches physical limits, at which point it's a hardscrapple expansion through the future lightcone for those rich enough to afford descendants), and that furthermore, EY knows it and has been trying to deceive the rest of us in order to fund an early AI, and thus grab a share of the Singularity pie for himself and a few chosen friends.

The thing that makes this seem implausible right now are that the SIAI people I know don't seem to be the sort of people who are into long cons, and also, their object-level arguments about the Singularity make sense to me. But, uh, I'm not sure that I can stake the future on my ability to play a game of Mafia. So I'm wondering if SIAI has come up with any ideas (stronger than a mission statement) to make credible their dedication to a fair Singularity.