Photo: Sinisa Kukic/Getty

If you’ve taken a break from gainful employment today to check Facebook, you’ve probably noticed a flood of strange check-ins: friends, from seemingly all across the globe, checking in this morning at the Standing Rock reservation in North Dakota. No, you did not miss a group vacation, and your friends have not suddenly decamped to participate in the ongoing protests there. It’s the result of a Facebook post that has gone viral, reading as follows:

The Morton County Sheriff’s Department has been using Facebook check-ins to find out who is at Standing Rock in order to target them in attempts to disrupt the prayer camps. SO Water Protectors are calling on EVERYONE to check-in at Standing Rock, ND to overwhelm and confuse them. This is concrete action that can protect people putting their bodies and well-beings on the line that we can do without leaving our homes. Will you join me in Standing Rock?

Interestingly, the movement’s success is due in part to the way it evades Facebook’s virality mechanisms. After the above message, the post goes on to ask users to check in publicly, but then clarify in a separate post to friends what they’re doing. It also has recommendations to maintain the ruse on the publicly viewable post, including using an alternate name and privately messaging people who send concerned well-wishes. Facebook is meticulously designed to incentivize shares and in-line conversation, but the Standing Rock protest has creating a mystique and drawn attention by stepping outside of those parameters.

A lot has been written about the inefficacy of hashtag activism—namely, that it creates a way for people to feel involved with a protest without actually risking anything—and it remains unclear whether or not this protest is working the way it aims to. For their own part, the Morton County Sherriff’s Department has posted on Facebook (where else?) that the claim is “absolutely false.” Still, it’s interesting that by withholding some information, the protest creates a demand for more. If interested in expressing support in a more direct way, the Sacred Stone Camp is accepting donations here.