Bye bye BetterSlack
This terrifies me, to be honest. BetterSlack is (was?) a chrome extension that modifies a web page. There are lots of these, and many of them are very useful. But what Slack is saying in their C&D seems crazy:
In order to remedy this, we ask that you please modify your product so that you are not forcing your own code into our services.
They claim that they have a TOS that forbids this, and I believe them. But do they have any legal basis for trying to shut down an author from distributing an original program? After a moment's thought, I doubt they do. But I'm not sure how the courts will see it. Blizzard had quite a bit of luck going after the author of a program that helped users cheat at WoW, but I think they had to demonstrate that the program hurt their business. I can't imagine BetterSlack hurts Slack's business.
I do think the author should change the name, though. Best to not mess with trademarks.