I'm not sure that democratic consensus is the same as democratic government. If the Silk Road 2 community grows and its new users have different ideals than the old ones -- maybe they don't support this kind of retribution against thieves, or they're against selling certain goods on Silk Road -- then a government would require new users to abide by the old rules, whereas a consensual arrangement would acknowledge that the consensus has changed.

If you do think that Silk Road 2 has some form of government, what kind is it? That is, how do they define and maintain their code of behavior? An oligarchy of old and influential users might claim to have authority; DPR 2 might act as a monarch; a majority of users might claim that everyone accepted a "social contract" just by joining Silk Road. But a de facto agreement among members on how to behave isn't enforced: it's de facto, so it happens to be the case, but it could change as easily as it formed.