Thousands of people are checking in on Facebook to a place they've never been to try and support protestors opposed to a new oil pipeline.
A post asking people to check into Standing Rock — where protestors are currently opposing the building of the North Dakota Access Pipeline — is spreading quickly online.
It asks users to check in at the site of the protest, wherever they might actually be, so that police can't use Facebook locations as a way of tracking down protestors.
The viral Facebook update asking people to make the change says that doing so will add to a huge virtual influx of people to the area.
As such, local police won't be able to pick the real check-ins from the fake ones — and one way of monitoring protestors will be avoided.
The update claims that police have been using that technique as a way of targeting people and disrupting camps.
It says organisers also known as "Water Protectors" are asking others to check in and "overwhelm them".
The update asks people to make a public post and set the location as Standing Rock.
It then instructs people to send another private post that explains the public one, and asks users to join in with the movement.
It still isn't clear whether police — who could not be reached to respond to requests for comment — are actually using Facebook locations as part of their work.
And it's also not clear whether protestors are actually using the technique or if it is just spreading as a viral hoax.
But in the meantime it appears to have morphed into a way of expressing solidarity with those protesting against the North Dakota Access Pipeline.
Activists have been camped out in Standing Rock since April but tensions are spiralling after protestors clashed with police and tents and vehicles were destroyed.
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