"miserable" mode. It was a mod introduced in vbulletin 2 by community members.

When installed it extended the idea of banning or shadow banning as it degraded the user experience for the person in question. Basically giving the impression that the site was malfunctioning to the point that it was frustrating for the user and they left the site for a while. This included random delays to the page loading, and sending them to a different page and ignoring their intent.

https://www.vbulletin.org/forum/showthread.php?t=93258

I believe Hacker News does this too (disclaimer: I have never experienced this firsthand, and the people I hear it from are obviously not impartial sources).

WeChat does it (as well) [0].

[0] https://citizenlab.ca/2020/05/wechat-surveillance-explained/

Facebook is doing this for a while. Pretty sure they always checked privately sent links. Some years ago I sent a .tk domain to a few friends and it got shadow banner after a few minutes (it was a harmless meme site).

Hackernews does shadowbanning as well.

It was done at the unnamed social network I worked at, over 10 years ago.

To combat spam, mostly. People posting links to scam sites to watch sports games.

When faced with software/malware that was appending links to user's instant messages back in 2005, back-end code to silently drop the user's messages was put in place. This was a messaging service that had ~200 million users.

Apparently by Facebook.

It takes a certain amount of hubris to think that because you and your friends left Facebook that this constitutes a “revolt.”

To move that needle requires hundreds of thousands or millions of people to act in concert. Scale matters.