The Internet isn't the anonymous playground of free goodies that many once thought it was. In fact, your online behavior could land you across the courtroom from a multibillion-dollar industry. The Recording Industry Association of America is cracking down on Web surfers who it claims have shared copyrighted music files over the Internet. The organization, which represents record labels, has sent hundreds of subpoenas in the past month to Internet service providers for the identities of file sharers, and it plans to begin filing lawsuits later this month and next month. The following questions and answers are intended to shed...