Echelon, the international spy network allegedly set up to listen in on civilians' electronic communications, will get some of its most public exposure to date this weekend, when a prominent US civil rights group runs a full-page advertisement in the New York Times Magazine and the New Yorker, both national American publications. The advert placed by the American Civil Liberties Union (ACLU) is designed to raise public awareness of Echelon, as well as the FBI Internet wiretap system called Carnivore, with the aim of forcing the US government to protect individuals' rights to privacy. It features an image of a mobile phone with the legend "Now equipped with three-way calling. You, whoever you're dialling, and the government." It directs readers to a Web site where they can find out more about Echelon and Carnivore, and where they are urged to send faxes to their representatives in Congress urging them to block Carnivore and investigate Echelon, about which little has been made public. "The same technological advances that have brought enormous benefits to humankind also make us more vulnerable than ever before to unwarranted government snooping," said Barry Steinhardt, the ACLU's associate director, in a statement. "Through this advertisement, the ACLU hopes to increase awareness of the privacy threat and mobilise our lawmakers into action." The ACLU argues that Carnivore and Echelon contravene the US Constitution's Fourth Amendment, which blocks unauthorised government surveillance. "Congress must cage Carnivore and determine if the Echelon programme is as sweeping and intrusive as has been reported," stated Gregory T Nojeim, associate director of the ACLU's Washington National Office. "Congress must ensure that our government does not intercept Americans' conversations without a court order." They can see you... Find out how and why in Surveillance, a ZDNet News Special. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet news forum. Let the editors know what you think in the Mailroom. And read other letters.