Kang "TheShy" Seung-lok, the top laner for Weibo Gaming, was streaming when his account was disabled.
This event, according to accounts, took place right after he had lost a ranked game. After that, he went into the lobby and noticed a message that his account had been banned right away. Confounded, he tried to rejoin several times, but to no use.
He was most definitely banned because of a new Korean server rule, albeit it hasn't been confirmed. Earlier this month, Riot Games Korea declared that "accounts rented to foreign pros have been suspended" as part of a broad range of actions to enhance the fierce competition in the LCK.