>>28699235
Those are all automatic plate readers. If they catch you going over the speed limit and get a clear read on your plate you get a letter in the mail with a link to a video exactly like what anon got here
>>28698741
They also log your car and any identifying features (make, model, paint, dents, stickers, etc.) into a database every time you pass one. This information is then licensed out to third parties, or accessed by an enterprising individual who has realized that these systems are rarely secured the way they should be.