Things are heating up on social media in the fight against the Dakota Access Pipeline.

As of Monday hundreds of thousands of Facebook users have “checked in” to the Standing Rock Indian Reservation.

Several posts on the social networking site describe the viral check in campaign as a way to confuse the Morton County Sheriff Department, whom they say has been targeting protesters via Facebook.

In a response on Facebook the Sheriff’s Department has denied the accusations, calling them “absolutely false”.

Others are checking as a showing of solidarity after a clash with authorities last Thursday resulted in the arrest of over 140 demonstrators.