They own the system, they could just shadowban bullies' votes. They could have just done it on videos that were statistical outliers, too - raised a "bullied" flag.

It'd be pretty easy to isolate different voting mobs, too, and group them together. You could use them to just ban the mob that is targeting the video, and let members of other mobs' votes still slip through. I might even inform the user if I were cocky about the system: "You have been prevented from voting on this video because your account has been associated with a mass-downvoting group from reddit.com/r/ronpopeillives. If you feel you have received this message in error, send an email to appeals@devnull.youtube.com."

I don't believe this at all. In any system where likes and dislikes have value to recommendations or whatever you have to identify and neutralize those who try to game the system. For example:

1. Sock puppets

2. Brigading

3. Bullying (which is really the dislike version of brigading)

That should be relatively easy to do at scale. Not perfectly but good enough. Once identified just count those votes as nothing. Present them as if the user has still pressed like or dislike but just don't count it.

Instead what Youtube has done has disincentivized people from disliking, which removes a very useful quality signal. Some will still dislike but less will if there's no feedback.

Dislikes provided a very useful signal to viewers about scams, poor videos, wrong information and so on. This provided a disincentive to post such information. So Youtube has removal that signal from users and effectively opened the floodgates to low-quality and scam videos.

That's just crazy.

And to pin that on "bullying" is (IMHO) ridiculous.