Le Van Phung, 32, was fined by police of the southern Binh Duong Province for inciting public disorder on Sunday.
On March 26, Phung used the account TikTok@phunguniexport to post a TikTok video calling for protests in front of Binh Duong's Dai Nam tourism area, belonging to Vietnamese tycoon and Internet celebrity Nguyen Phuong Hang and her husband, in support of Hang.
Phung has since removed the video and promised not to repeat similar violations.
Hang, 51, was arrested last month after criticizing multiple celebrities in Facebook livestream videos. She is being investigated for "abusing democratic freedoms to infringe upon the interests of the State, lawful rights and interests of organizations and/or citizens."
In February, Hang was temporarily banned from leaving the country until the end of April following multiple accusations of slander and insults.