A、There are too many complaints from net users. B、Hackers’ attack of MySpace cannot be forbidden. C、Parents cannot help checking

MySpace, the social networking website, is different from other websites which only provide stories about other people. MySpace is a place that allows you to broadcast your own stories and personal information to as many people as you like. Started two years ago, it is a big source of information for and about American kids.
    Teens are rushing to join the site, not sharing their parents’ worries. For teenagers, it is reliable network to keep in touch with their friends. They will often list their surnames, birthdays, school clubs, hobbies and other personal information. "MySpace is an easy way to reach just about everyone. I don’t have all the phone numbers of my acquaintances. But if I want to get in touch with one of them, I could just leave them a message on MySpace," said Abby Van Wassen, a 16-year-old student. Since each user’s personal home page lists the number of their MySpace friends, it has become yet another way of judging high school popularity. MySpace has become something teenagers feel they must have.
    Parents on the other hand are seriously concerned about the security problems of MySpace. The National Center for Missing and Exploited Children has received at least 288 MySpace-related complaints, according to Mary Beth Buchanan, a lawyer in Pittsburgh. "Your profile on MySpace shows all your personal information to anyone on the Web. And MySpace even lists this information by birthplace and age. It’s like a free checklist for trouble-makers and it endangers children," Buchanan said.
16. What is the difference between MySpace and other websites?
17. What do we learn from the passage about MySpace?
18. What is the security problem of MySpace according to Buchanan?
19. What does the passage mainly talk about?