I believe that the technical term here would be "dick move".
I used to use a self hosted blog aggregation software (Gregarius) and put it up at www.mypersonalsite.com/blogs that was unlisted and unlinked to. It got 3 uniques/month for about 12 months. Then one day a company owner (a regular from the Joel on Software's forums -- a technical person) wrote a blog post linking to my site, calling me a spam blog, and posted my personal information. He sent my host a C&D, and also blocked my work IP (most of the local IBM office) from reading his blog.
From what I gather, he looked at his refer logs and saw I clicked through to his blog 2-3 times, went to the link and freaked out that I was displaying his RSS feeds.
I emailed him to try and clear it up, and was quite polite, but he kept being an asshole, accusing me of stealing his content and breaking the law. He threatened me with further action, and was condescending because I was 17. ("You should password protect your 'blog reader' as a learning exercise, then blog about it so you'll have content of your own and you won't have steal my content").
He never reached out to contact me. He just sent the C&D, wrote a nasty blog about me, and didn't even try. Once he jumped to conclusions, it was too late.
The only thing to add is great minds are more generous and less concerned with violent retribution to compensate for a lack of control in their own frustrated lives.
Others have a 4 letter word for it....
cool.
If something is really offensive or stolen, it is tough as hell to remove all traces of it- anyone could have a copy. The lesson learned here is if you are that pissed off that someone shared it, the problem is that someone shared it, not the person who took it. Unless it is crack being given to a crack dealer, but that's different. Git repos aren't crack houses. Not usually. Ok, maybe some of them. But not many. Just one? Ok just one.
To me, this really emphasizes the importance of communications, followup (the human timeout and retry factor, especially when the Github people are hinting that they replied and it was somehow missed), and patience instead of kneejerk reactions.