Anti-Smurf measures for ranked.

Smurf accounts boosting within ranked has always been an issue for as long as the ranked seasons have gone on, often making it unfair or infuriating to play against in the lower rungs or during placement matches. However, I think Riot could take a page from Valve in order to better fight against this sort of thing by requiring you to register a phone to your account to play ranked. This would make it so you could only have one account for ranked play, period. I think this would go a long way to help make matches less toxic, but I'd like to hear your opinions on the matter.