Is it okay if a student threatens teacher online?

No, it is absolutely not okay for a student to threaten a teacher online. Online threats are taken very seriously and can have serious legal consequences for the student, including suspension from school, expulsion, arrest, and criminal charges. The severity of the consequences depends on the nature of the threat. Even seemingly harmless threats can be interpreted as serious depending on the context. It's crucial for students to understand that online communication is not anonymous and that their actions have real-world repercussions.