[mumblemumble]

It wasn't even that many people. Maybe (and generously, I think) 100 commenters out of ~400,000 people who got notified? That's 0.025%.

[zenexer]

All of those 400k people were notified because the author tagged a group containing 400k people. For every comment, 400k emails went out.

I never commented, but I received an email for every comment in that issue. The email queue was so backed up that I was receiving emails for quite some time after the issue was closed.

[blensor]

And some troll did the same thing with another pull request about 2 hours ago.