SEOUL -- Ko Sung-kook's office in Seoul buzzed as researchers prepared show notes and a constant flow of visitors filtered in and out of the cramped space.
Recent violent attack and upcoming elections draw scrutiny of influential platform

Ko Sung-kook operates a popular YouTube channel offering political commentary. (Photo by Steven Borowiec)
SEOUL -- Ko Sung-kook's office in Seoul buzzed as researchers prepared show notes and a constant flow of visitors filtered in and out of the cramped space.