My blog post for Harvard Business today looks at the troubling online reaction to last night’s riots in Vancouver. Reflecting on the widespread enthusiasm for using social media to track down criminals, I wrote:

I don’t think we want to live in a society that turns social media into a form of crowdsourced surveillance. When social media users embrace Twitter, Facebook, YouTube and blogs as channels for curating, identifying and pursuing criminals, that is exactly what they are moving toward.

The reaction to my post has been intense. Many people seem to read my concerns about social media surveillance as an argument to let rioters off the hook. On the contrary: I hope that everyone who engaged in criminal activity last night is held accountable.

But there is a big difference between individuals cooperating with law enforcement — carefully, thoughtfully and with discretion, to reflect the presumption of innocence — and an online mob that has taken the job of law enforcement into its own hands. A Facebook page is gathering pictures and comments from thousands of people who are offering to help identify riot participants. A Tumblr site is crowdsourcing the creation of a Vancouver 2011 Riot Criminal List. And now Premier Christy Clark is going beyond a simple request to share pictures with police, and suggesting that people do so publicly:

Vancouver police are asking people to email their photos and videos to robbery@vpd.ca, or post information through Twitter at #VPD.

What makes this especially peculiar is the the Vancouver Police Department’s own statement encourages people to submit photos via email, and to share their videos privately on YouTube.

The fact that the police department itself is encouraging people to share their photos and videos privately should tell us a lot about the troubling territory social media users have wandered into. There is a reason that the state has been defined by its monopoly on the legitimate use of force: delegating law enforcement to professional police is a way of preventing vigilantism, ensuring due process and protecting civil rights.

Just as crucially, professional law enforcement protects a healthy civil society from the corrosive effects of citizen surveillance. When citizens take on the job of reporting on one another it can lead to some very dark places, very quickly. One of the most difficult revelations to emerge in the wake of German reunification was the sheer number of civilians who cooperated with the Stasi, East Germany’s notorious secret police. About 5% of East Germans were secret informants, a culture of crowdsourced surveillance that eroded social trust and perpetuated an authoritarian state.

Precisely because social media is such a powerful tool of mass mobilization, it has the potential to turn selective cooperation with law enforcement into a mass culture of surveillance. That’s a culture in which a key responsibility of law enforcement — the tricky job of surveillance — is outsourced to citizens instead.

Police forces are typically major proponents of gun control because they know exactly what is at stake when citizens begin to take the law into their own hands.  And “taking the law into your own hands” doesn’t have to involve administering vigilante justice with a gun. It can look like people creating their own Wanted posters. It can look like employers making decisions based on online information instead of criminal records. It can look like organizing a mass, volunteer corps of police informants — exactly what is going on today.

We have seen Big Brother, and he is us.