When an Internet prank turns serious, Sean becomes the main suspect Bored in computer class, Sean Quinn and his friend Matt decide to liven things up with a little computer prank. But the laughs stop quickly when they accidentally hurt a younger student's feelings, earning themselves a quick trip to the principal's office. That night, Sean receives an anonymous email praising him for the prank, and promising to avenge his punishment by causing trouble at the school. The next day, a virus wreaks havoc with the school computers, and the principal suspects Sean of being the mastermind!   To keep himself out of trouble, Sean asks his brother Brian to help him find the hacker behind the anonymous email. Catching criminals in the real world is tough enough, but when a crook decides to hide behind the computer screen, it will take every trick in the Casebusters' arsenal to bring this cyber-thug to real-world justice.