On Tuesday night, more protesters marched across U.S. cities to push back against police brutality and the killing of unarmed Black man George Floyd by a white police officer. And overhead, in cities such as Las Vegas, Washington DC, and Portland, the National Guard and law enforcement flew surveillance planes, according to flight data reviewed by Motherboard.

The data shows that flying high-tech and traditionally military-focused aircraft above protesting cities is becoming a norm at this time.

"Military surveillance planes over America's cities are a rare visible indicator of tectonic increases in surveillance quietly underway," John Scott-Railton, a security researcher who has also been tracking some of the surveillance aircraft flights, told Motherboard.