Mine is a simple — dumb, even — adaptation of Metcalfe’s Law.

“The security and privacy risks increase proportionally to the square of the number of users of the data.”

— First quoted in this eWeek article about the electronic employment verification system included in the current immigration bill.

(I actually suspect that Briscoe’s et al’s refinement of Metcalfe’s law is more accurate, but that’s just so complicated.)