Many have heard about Madison Common Council Alder Rebecca Kemble being arrested at Standing Rock. She was arrested apparently for her work as an NLG Legal Observer. Here is a video interview about her Legal Observer work and her subsequent arrest.
Note as well that Dane County Sheriff's deputies had been at Standing Rock through a call for mutual aid from North Dakota police. After more information about what was going on in Standing Rock became available, those Dane County deputies were pulled and are no longer there. Kudos to Sheriff Mahoney.