I would say it's 50/50 between Reyna and Jett.
Every single game I play, there is at least one Reyna or Jett that is top fragging on one of the teams. And by top fragging I mean to the tune of 30 kills.. usually something like 30.10.
They won't ban them, because it's another account. It makes the playerbase look bigger than what it actually is.