Here is an example of a Wikipedia admin who spent years harassing a blogger (and a community the blogger belongs to), and it took a lot of effort and a lot of luck to make other admins admit that this was a bad thing and that it should stop.
(This is not the worst example I know of, but it is an example where Wikipedia changed its mind later, so you can agree that this was bad even if you trust Wikipedia.)
https://en.wikipedia.org/wiki/Wikipedia:Administrators%27_no...
Here is an example of a Wikipedia admin who spent years harassing a blogger (and a community the blogger belongs to), and it took a lot of effort and a lot of luck to make other admins admit that this was a bad thing and that it should stop.
(This is not the worst example I know of, but it is an example where Wikipedia changed its mind later, so you can agree that this was bad even if you trust Wikipedia.)