Will qq be blocked by friends because they read something they shouldn't, or will Tencent send a message to inform them that it is blocked? Is that so?

That depends on the severity of your behavior. If it seriously endangers the security of the party, the country, the people and the society, or seriously violates the provisions of the Supreme Constitution, Tencent has the right to force the title without informing itself. If it is not particularly serious and can't stand the report of others, Tencent will have information to inform you to terminate the illegal act within a time limit. If it is not terminated within the time limit, the system will still force the title!