"Up to 10 informants managed by the FBI were embedded in anti-pipeline resistance camps near the Standing Rock Sioux Indian Reservation at the height of mass protests against the Dakota Access pipeline in 2016."

This seems obvious: there are informants in any major protest movement, and have been since there were protest movements. It's not great, and it's a fundamentally undemocratic way to conduct yourself, but it doesn't represent a change from the status quo.

This article talks about surveillance, but of course, there may have been situations where informants and plants actually set out to undermine the protest. This, too, would not have been a change. #Democracy