More than 1 million people have "checked in" at Standing Rock Indian Reservation in North Dakota on Facebook on October 31. The mass "check in" was in response to a viral post calling for help to protect activists in North Dakota protesting against the Dakota Access oil pipeline from police surveillance through the Facebook feature.
"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,” the text of the viral Facebook post said.