Alva Review-Courier -

From the perspective of teens, TikTok is a major new outlet for self-expression, one proudly home to the silly, the loud and the weird.

To others, the Chinese-owned online video service is an unnerving black box that could be sharing information with the Chinese government, facilitating espionage, or just promoting videos and songs some parents consider lewd. (TikTok denies the first two concerns and says it's working on the third.)

Welcome to the bifurcated world of TikTok, an emerging social-media powerhouse that lets users create and share short videos, many no longer than 15 seconds. "That...