alt Hacker NewsKnives were too, and yet I'm not calling people to use forks instead. There is a difference between military contractors and generic tools.
Edit: sorry, hotheaded reply. I assume you mean that the creator of mIRC was encouraging it (though it's not mentioned anywhere). I still.stand by my analogy, but I see your point given your assumption.
> I assume you mean that the creator of mIRC was aware of it and encouraging it.
Like most licensed software, it was likely licensed by “US Government” or “Department of Defense”. Plus, it was openly written about back in the day. It was well known. No clauses in their licensing to prevent its use for those purposes.
Comparing to Mattermost and amplifying the original comment, Mattermost website is openly associating with PlatformOne.