In the case of Discord which would be today's MSN Messenger, it's not often done because your account will be terminated if you are found to be using a modded client.
[0]: https://nitter.42l.fr/discord/status/908000828690182145
I don't have beef in the game, FWIW. I have greasemonkey loaded in my firefox and inject a bunch of custom mods in various webpages, including discord, to automate various parts of my workflow. Discord could probably detect it and ban me, but I guess so long as I don't use it for nefarious purposes, they won't.
I thought Discord uses Qt?