You can look at leaked source code for educational purposes in most places (not legal advice). As far as I understand leaks are commonly used in vulnerability research for example (if the bad guys can use it so can bug hunters).
Streaming copyrighted material is a separate issue - but using it for "criticism, comment, news reporting, teaching" should fall under fair use, no?
I can certainly understand why twitch banned this and don't blame them (although I think it's stupid), but I see nothing unethical about openly talking about this code in the public now that it's already there.
Copyright would disagree with you, and I would say that ethically it is basically the same as stealing it yourself. You're profiting off of someone else having done the dirty work for you.
> this isn't someone's personal life being exposed.
Apparently a lot of payment information, telephone numbers, etc. was also in the leak. I don't think we should downloading or encouraging people to download and peruse that stuff.
