It is generally illegal to harass others on WeChat and does not constitute a crime, but it can be punished by the public security organs. Generally speaking, the person will be detained for not more than five days or fined not more than 500 yuan; if the circumstances are serious, he will be detained for not less than five days but not more than 10 days, and may also be fined not more than 500 yuan.
Legal objectivity:
Article 42 of the "Public Security Management Punishment Law" who commits any of the following acts shall be detained for not more than five days or fined not more than 500 yuan; if the circumstances are serious , shall be detained for not less than five days but not more than ten days, and may also be fined not more than five hundred yuan: (1) Those who write threatening letters or threaten the personal safety of others by other means; (2) Those who publicly insult others or fabricate facts to slander others; 3) Fabricating facts, making false accusations and framing others in an attempt to subject others to criminal prosecution or public security penalties; (4) Threatening, insulting, beating or retaliating against witnesses and their close relatives; (5) Repeatedly sending obscene, insulting, threatening or other information that interferes with the normal life of others; (6) Peeping, filming, eavesdropping, or spreading other people's privacy.