It’s Cracked, so take it with a grain of salt until others confirm, but there appears to a massive law enforcement censorship effort going on at Standing Rock. TL:DR – law enforcement agencies from multiple states are using planes and drones equipped with Stingrays to disrupt the ability of cell phones at Standing Rock to connect to the internet. They’re coupling this with DDoS attacks aimed at the camp’s secure wifi hotspots along with their own honeypot unsecured wifi hotspots designed to hack protesters’ devices and accounts. This is censorship on the level of Egypt trying to shut down the internet during the Arab Spring.
No one could be bothered to follow up on the AP article cracked mentions?
I’m having trouble tracking down any article the AP themselves wrote on their investigation, but here’s Tech Dirt talking about it back in 2015. https://www.techdirt.com/articles/20150602/10125531189/ap-uncovers-more-than-100-fbi-spy-plane-flights-originating-shell-companies-located-virginia.shtml