A troll exploits social dynamics like computer hackers exploit security loopholes, and Violentacrez calmly exploited the Reddit hive mind's powerful outrage machine and free speech values at the same time. It was this pattern, repeated to various degrees dozens of times, that made Violentacrez an unlikely hero to many of the white male geeks who make up Reddit's hard core. They saw Violentacrez as a champion in the fight against the oppressive schoolmarms: "He upheld a certain amount of freedom for the worst of us to ensure freedom for all of us," wrote one user in a post mourning his departure. Fans followed him wherever he went on the site.
Reddit should take control of its reputation. Its "common carrier" aspirations—already proven to be unsustainable—seem to prevent it from exercising some much-needed quality control over what moderators do in top subreddits. And lest you think that its hands-off policy is about preventing censorship, remember that links to Gawker are currently banned on some top Reddit-promoted areas such as /r/politics.
Letting creeps and criminals speak for you is no defense of free speech: it's just an invitation to be measured by what they say and do in your name.