13 sec video of a Chinese click farm (quite loud):
https://twitter.com/mbrennanchina/status/1072114511212109824
10 sec - thousands of phones (not loud):
https://twitter.com/mbrennanchina/status/1148447866366464000
I had a private contact within google's SRE team and spilled all the beans, ask where I should dump the information within google. The answer was as blunt as telling: no one would be interested since it would hurt their bottom line.
Tried to inform a couple of Googlies at different cons in the months following: as much as they liked the tricks we pulled to get in, as little did they want to bring the subject up in their teams.
Clicks are Google's Crack.
Those who run the bot farms will find other scummy work, and no end of desperate workers.