Illegal. According to the Interpretation of Several Issues Concerning the Application of Laws in Handling Criminal Cases of Infringement of Citizens' Personal Information, it is illegal for educational institutions to exchange telephone numbers, which constitutes a crime of infringing citizens' personal information. Legal business activities infringe on citizens' personal information, which requires that the information should not flow out and spread again, that is, the behavior mode is limited to buying or receiving, and the illegal sale or provision of citizens' personal information by operators should not be regarded as legal business activities, and the criminalization standard should be applied. Subjectively, training institutions exchange and provide citizens' personal information, and the purpose of exchanging and obtaining citizens' personal information is to legally operate education and training business. Both providers and buyers are for legitimate business purposes, not for the purpose of illegally profiting from reselling citizens' personal information. Compared with resale, subjective malignancy is less.