The Dunbar's Number complaint doesn't really seem to apply here. New members couldn't compromise anyone else (we know because they tried), so quality control f

The Dunbar's Number complaint doesn't really seem to apply here. New members couldn't compromise anyone else (we know because they tried), so quality control failures only punish the people who fail to control quality. As a 'distributed' system it was basically safe for reliable users, and could reasonably continue operating while compromised. That's not a total success by the group's goals (people got caught, and they got monitored), but they lost their keys, got subverted by their own members, and still didn't lose their anonymity.