Any way to report multiple accounts at once?

Howdy all, having a mild problem at the moment.

Some veigar joined our team today, and proceeded to spend the entire game griefing, following me around and attempting to steal any monster i tried to get. Im actually making this forum post now, during said game, because i am completely incapable of doing anything and ive had to spend most of the game wandering around spawn. We still have about 20 minutes left before we can call a surrender that will work with 4-1, and i dont want to alt-f4 for obvious reasons. The rest of my team are kinda doing the same thing as me.

The veigar pushed off the threat of a report by saying they had 20 accounts. I doubt that, but is it possible to report multiple accounts from the same source? Email, or something?