Notification when Reported: Instant feedback is too instant.
Recently, people I report seem to get instant notifications when I report them. I don't know if there's a name attached, or if they're just good at guessing, but invariably, after I report somebody, they then rage at me and redouble their verbal abuse. This has happened three or four times in the past week.
I report people because I am uncomfortable being verbally abused. If reporting people makes me a target for further verbal abuse, I am therefore less likely to report people. I'm sure it's not the intent of your system to make players feel punished for reporting people. Especially when the players most in need of reporting are the ones most likely to abuse you for hitting the report button.
I recognize and agree that the sooner people get feedback, the more likely they are to change. But seriously, could the "you've been reported" notification be changed to it pops up when you leave post-game chat? That'd be helpful to the people doing the reporting.