As thousands of protesters demonstrated in Hong Kong against Beijing’s rejection of open election nominations, drones flew above their heads to capture those memorable moments. This video, published on Facebook on Monday, shows crowds in the city's central business district, according to Storyful.

Thousands of demonstrators filled the streets in Hong Kong Monday to protest Beijing's decision to reject open nomination calls for the election of Hong Kong's chief executive in 2017. (Facebook: Nero Chan)

It's not the first time that drones have shot videos of demonstrators. Over the past few years, videos shot by drones have gone viral on the Internet and caused reactions ranging from distress to amazement. Here is a selection of some of the most impressive (and at times disturbing) drone videos of protests.

Bangkok, Thailand

These two clips were uploaded in late 2013 and early 2014. While the first video shows clashes between police and protesters, the second one focuses on another detail: The emptiness of streets in Bangkok during the protest shutdown.

Kiev, Ukraine

This drone takes us to Ukraine's Maidan Square in Kiev in late 2013 when protesters demanded the resignation of Ukrainian president Viktor Yanukovych. What is striking is the visual difference between the protests at day and night.

Taksim Gezi Park, Turkey

This video was uploaded in 2013 and appears to show Turkish protesters in the Taksim Gezi Park. Referring to the same YouTube account, Wired reported in 2013 that Turkish authorities deliberately targeted civilian drones capturing the protests from above.

New York City, U.S.

Sept. 21, more than 300,000 protesters united in New York City to raise awareness for the repercussions of climate change.

Warsaw, Poland

These two videos, which appear to have been taken during Polish Independence Day in 2011, seem more like the opening minutes of a movie than real footage. The drone rises toward the sky, and soon Polish police officers appear in the shot. The drone camera turns and follows the officers through the streets of Warsaw, preparing for clashes with demonstrators.