Why should Chinese public education invite people to collect student numbers?

General educational institutions will collect students' information extensively, so as to contact them when offering courses in the future, and will also strive for students from various schools. Therefore, they often receive well-known and unknown information from various educational institutions. They may have inadvertently filled in what information they have found, or they may have some special methods. So now, their mobile phone number information has been largely exposed, which has actually become a problem for some people. After all, it is very distressing that you call or send text messages to disturb other people's lives.