The boy, whose name has not been disclosed, a student of the Ngo Quyen Secondary School in Ho Chi Minh City’s Tan Binh District, is barred from classes from Wednesday until Saturday and has been forced to make a public apology Tuesday in front of the whole school.

Last June, he created a fanpage called "Anti BTS in Vietnam" and posted articles and photos of members of the boy band, using "inappropriate" language to criticize them, the school leaders said.

BTS is a highly popular South Korean boy band in Vietnam, known for their boyish good looks and meticulously choreographed dance moves.  

The controversial articles using "inappropriate language beyond the thinking of a secondary school student" and violating the Cybersecurity Law had outraged fans of the music band, prompting the school board to take disciplinary actions, said Nguyen Ngoc Thu, vice principal of the school.

Thu said the boy’s behavior violated ethics, school rules as well as the law.

"Whether it's the BTS music band or anyone else, the use of social media to insult others is unacceptable," he said.

Vietnam ranks seventh in the world in number of Facebook users with 58 million, or 75 percent of the population aged 13 or more, according to a report released in July by U.K. advertising agency We Are Social.

An average Vietnamese uses social media for two hours and 23 minutes a day, same as the global average, according to market research firm GlobalWebIndex.

Vietnam’s Cybersecurity Law, which took effect earlier this year, bans internet users from humiliating and seriously offending the honor, prestige and dignity of other people or posting false and untruthful information that damages the legal rights and interests of other organizations and individuals.

It also bans users from organizing, encouraging or training other people for anti-state purposes, distorting history, negating the nation’s revolutionary achievements, undermining national solidarity, offending religions and discriminating on the basis of gender and race.