With all of the protests that have been going on all over the world for the past year, and with all of the footage being posted on video sharing websites like YouTube, there's a lot of concern or privacy. To help with those concerns, YouTube is adding a facial blurring feature that, when enabled, will take your video, detect and blur the faces in it, give you the blurred video, and give you the option to delete the original video. Of course, this technology is still in its infancy, so face detection isn't always spot on, but as time goes on it will get better. Below is an image of before/after the blurring tool was used.
It really is quite simple to use, all you do is click a button and the tool will do all the work for you. As I said, it might not get all of the faces in the video, but it should get the more obvious ones. It depends on video quality, lighting, angles, and other such things. Read the original blog post here.