Is it illegal for teachers to watch students' mobile phone text messages?

Law of People's Republic of China (PRC) on the Protection of Minors

Article 39 No organization or individual may disclose the personal privacy of minors.

No organization or individual may conceal or destroy minors' letters, diaries and emails; No organization or individual may open or consult the letters, diaries and e-mails of minors without legal capacity, except that the public security organs or people's procuratorates conduct inspections according to law in order to trace crimes.

I. Constitution of People's Republic of China (PRC)

Article 38 The personal dignity of People's Republic of China (PRC) citizens shall be inviolable. It is forbidden to insult, slander, falsely accuse or frame citizens in any way.

Fortieth the freedom and privacy of communication between the people of China and the citizens of People's Republic of China (PRC) shall be protected by law. When public security organs and procuratorial organs check communication according to the procedures prescribed by law, no organization or individual may infringe upon citizens' freedom and privacy of communication for any reason, except for the needs of national security or criminal investigation.

Especially article 40, you have a good look. Slander or defame the reputation of a legal person in written or oral form, which causes damage to the legal person, shall be deemed as an act of infringing on the reputation right of a legal person and your reputation right.

Don't think that being a teacher is great, minors still have personal privacy!