A group of Ukrainian software developers say they've developed several programs that can turn America Online’s ICQ instant messaging software into a spy tool, and AOL is battling to keep the programs off the Internet. A Web site distributing the rogue programs first sprang up in the autumn, but the programmers just started aggressively marketing their tools this weekend. Meanwhile, AOL Time Warner lawyers have sent threatening letters to Web hosting providers and partners supporting the Ukrainian team, according to one former partner. The suite of add-on programs designed for AOL's ICQ software are advertised as offering the ability to impersonate other ICQ members, sniff out Internet Protocol addresses and even steal ICQ numbers. "Do you think it necessary to steal someone’s [User Identification Number] to talk with other people from it?" boasts the group’s Web site. "With this great program you can send and receive messages from any UIN you want! Now you can find out all secrets of your enemy or have fun on your friends -- try and enjoy it." Attempts to contact the programmers for this story were unsuccessful, but MSNBC.com was able to contact a former business partner. Igor Yagolnitser, owner of Ultima Gold, said he served as the programmers’ US accounting service earlier this year, helping them take payments in US dollars. He backed away from the group after receiving several threatening letters from America Online lawyers in December. Yagolnitser said the programmers believe they are making legitimate software to enhance ICQ services, and some of their products offer more mainstream uses -- such as "ICQ Server", which lets users create their own ICQ "intranet". That would let a group create its own ICQ network and send messages that never flow through America Online’s ICQ servers. Yagolnitser compared the ICQ impersonation software to other email tools, which also allow users to alter their "from" email address and pretend to be someone else. "If you decide to take the software and do the meanest possible thing it would be illegal. But ultimately it is your crime not theirs," he said. "There are multiple practical uses for [the software]. Say you are at a friend’s house and want to send a message as if it came from you." But he conceded that America Online has a legitimate complaint against the group because they are "cashing in on the popularity of ICQ". So far, the group’s marketing efforts have met with lukewarm success. When Yagolnitser served as the group’s accountant, only a few dozen users paid for the software, which costs $30 -- but it’s offered for download with a free 30-day trial, and according to the group’s Web site, over 100,000 surfers have visited. ICQ (like "I Seek You") is easily the world's most popular instant messaging software, claiming 90 million users. America Online bought the Israeli company that makes the software, Mirabilis, in 1998. Instant message software has since become a major source of new members and controversy for the firm. Microsoft and Yahoo! engaged America Online in an "instant message war" during 1999, as AOL's rivals tried to interconnect their message systems with America Online's instant message service and were rebuffed. That controversy ended up becoming one of the sticking points as AOL sought government approval of its purchase of Time Warner, which was finally granted earlier this month. AOL has apparently been just as aggressive in protecting its ICQ franchise and against the efforts of the Ukrainian programmers. Yagolnitser said that the Ukrainian programmers have already been dropped by two Internet providers after AOL complaints. America Online has filed complaint with the World Intellectual Property Organisation saying the group is using a Web site that infringes on its trademark, according to AOL spokesperson Jim Whitney. Spokesperson Nicholas Graham added that any ICQ user who tries the "spy" software would be breaking ICQ’s terms of service and be booted off the service. "If we encourter somebody using it in a way that makes the online experience hazardous for one of our customers, we would [kick them off ICQ]," Graham said. The programmers also did not respond to emails from MSNBC.com. But according to the Web site, the group was founded this year in Kiev, Ukraine. The programmers may believe they are offering a legitimate software product, and their site appears to be a traditional e-commerce site -- it even accepts PayPal payments. But the site used to distribute their software has questionable origins. Users who try to download their software are quietly redirected to another Web site -- Lkuy.com. But both that site’s content and its Internet registration information have been faked. According to NetworkSolutions.com, the site was registered to Debbie Meyers of Texas. Myers, who runs a rock band booking service named Bravo4u.com, told MSNBC.com she had never heard of LKUY.com. A spokesperson for Internet Domain Registrars said the site was registered fraudulently with a stolen credit card and would be shut down Wednesday. And the content of Lkuy.com contains nothing but links to Web pages owned by Gamma Entertainment, an adult content company. Karl Bernard, a spokesperson for Gamma, said he hadn't heard of LKUY.com either, and didn't sanction the site’s use of his company’s content. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Security forum. Let the editors know what you think in the Mailroom. And read what others have said.