The FBI has recently adopted a novel investigative technique: posting hyperlinks that purport to be illegal videos of minors having sex, and then raiding the homes of anyone willing to click on them. Undercover FBI agents used this hyperlink-enticement technique, which directed Internet users to a clandestine government server, to stage armed raids of homes in Pennsylvania, New York, and Nevada last year. The supposed video files actually were gibberish and contained no illegal images. A CNET News.com review of legal documents shows that courts have approved of this technique, even though it raises questions about entrapment, the problems of...