A who's who of musicians have written to US President Barack Obama, protesting the treatment of Standing Rock Sioux tribe members trying to stop the Dakota Access Pipeline.
The letter was written by British musician Kate Nash, and signed by rockers including Billie Joe Armstrong from Green Day, Ed O'Brien of Radiohead, Nick Mason from Pink Floyd, Karen O, Brian May and Cat Power.
"We are deeply disturbed by the police actions that have been taking place, where non-violent protests have been and continue to be met with extremely aggressive tactics including; being shot with water cannons in below-freezing temperatures, chemical weapons, rubber bullets and attack dogs. These are the same inhumane methods used during WWII and the civil rights movement," the letter reads.
The Dakota Access Pipeline would connect the oil rich area of North Dakota to Illinois. It is opposed by the Standing Rock Sioux tribe, who say the controversial project would destroy sacred burial and prayer sites.
The tribe is supported by a coalition of indigenous and environmental groups - and the activists have said they will not follow a federal-issued eviction notice to leave Standing Rock, despite threat of prosecution.
Ms Nash told Rolling Stone her letter - which is also addressed to the Department of Justice and Army Corps of Engineers - was raising awareness of important social issues.
"Since the election I have felt more than ever the necessity of activism and using the platform I am lucky enough to have to try and do something useful," Nash said.
"I've been thinking of ways that musicians use their voices and what connects to people in a social media-led world. I was curious as to whether my Twitter followers actually knew what DAPL and Standing Rock even was so I just asked them and a lot of fans admitted they didn't.
"That's when I realised I only knew about it because of my circles. It hasn't been getting much media coverage and people don't even know this is happening."