Why are candidates' personal information about the college entrance examination known by some schools or people?

1. The personal information filled in by college entrance examination candidates when registering for the college entrance examination will be maliciously leaked by some people with ulterior motives, resulting in the information of candidates flowing into the society.

2. There are roughly three possibilities for candidates' information to be leaked, namely "hacker" attack, "insider" disclosure and "manual" collection by intermediaries or organizations.