E/CN.15/2002/8 and the presence of effective security features had become an important factor in the decisions of consumers shopping for new products. 6. The use of technical security and crime prevention methods continued to expand during 2001, a reflection of the nature of the technologies, their continuing expansion and the difficulties encountered by traditional legislative and law enforcement responses, in particular in transnational cases. These included established products such as programs to identify and screen out hostile programs such as worms and viruses from stored and transmitted data and barrier products such as firewall software. “Geolocation” programs, which identify the geographical source of online communications, were used increasingly to deny access to those located in jurisdictions where gambling, pornography or other activities are illegal. This was greeted positively by the law enforcement community, but criticized by advocates of a completely open Internet and experts who pointed out that the effective use of such programs depended on the willingness of web-site operators to use them and on their knowledge of the legal restrictions imposed by other countries. Most experts also agreed that such programs effectively prevented accidental breaches and were effective against unsophisticated offenders but not against more knowledgeable offenders, who could easily conceal their true geographical locations from the software and web-site operators using it. The use of filtering software, which identifies and blocks content inappropriate for children or other unauthorized users, also continued to expand and many operators of adult web sites incorporated products intended to trigger such software. Cryptographic applications were also used to protect sensitive communications and prevent users without permission from gaining access to proprietary or sensitive data. 7. Within the law enforcement community, investigators with the skills needed to intercept communications in high-speed, digital media, conduct successful searches of stored data, decrypt encrypted data and perform other similar functions were recognized increasingly as a scarce, valuable and specialized resource. Many agencies have now established specialized units, called upon to assist other investigators in areas ranging from counterterrorism to drug trafficking and economic crime. Major concerns include the high costs and long-term investment represented by training investigators, the difficulty of retaining skilled investigators who can command higher salaries in better-funded private sector jobs and the simple problem of ensuring that investigators keep abreast of the deployment of new technologies and the latest criminal techniques for using them. 8. Member States are concerned about the potential offensive and defensive uses of new technologies by terrorist organizations and such concerns have been heightened considerably by the attacks of 11 September 2001. Experience shows that sophisticated terrorist offenders are already using the Internet to communicate. In that context, strong encryption and other security products have been used defensively to shield communications and stored data. The potential for offensive uses in support of terrorist objectives has also led a number of countries to establish specialized agencies dedicated to protecting data-processing, communication and other critical high-technology infrastructure from cyber-attacks. 9. The investigations that directly followed the September attacks also disclosed the use of the Internet to obtain information that could be used to plan attacks or obtain materials needed to make or improvise chemical, biological or radiological weapons. Several States that responded to a United Nations survey on, inter alia, the criminal misuse of explosives expressed their concern about the availability on the Internet of information about how to produce explosives and how to make explosive devices;4 and a person arrested in connection with an attempt to detonate an explosive device concealed in his shoe while on board a commercial flight from Paris to Miami on 22 December 2001 was reported by media sources to have told investigators that he had made the device using information obtained from the Internet. Similar concerns were expressed on the part of agencies involved in drug law enforcement with respect to the availability of online information about how to produce synthetic drugs and where to obtain the necessary ingredients. 10. Other computer-related and high-technology offences also continued to raise concerns during 2001. Among the more prominent was the use of digital technologies and the Internet to produce and disseminate child pornography. Several participants in the Second World Congress against Commercial 3