A group of Internet activists are hoping to bring attention to the US-led communications spy network, on 21 October, with a "Jam Echelon Day", but privacy experts are certain that the protests will have a minimal effect on the sophisticated surveillance system. Organisers of the cyber-event are encouraging the Internet community to send out as many email messages as possible, containing certain "trigger words", which the Echelon system is believed to pick up on. If the bulk of monitored emails becomes too great, the theory is that the Echelon intelligence system will be overworked with intercepting spurious input, and so its effectiveness will drop. But even though the organisers themselves concede that they are unlikely to be able to jam the whole Echelon system, they believe it is still worth pressing ahead. "While the goal of jamming Echelon is a lofty, and likely, unattainable one, is it not better to signal displeasure at being monitored, than passively allow it to happen," said the coordinator at cipherwar.com, who prefers to be known by his nick-name, 'Scully'. A list of 1,700 suspicious words have been listed on the Cipherwar Web site, to be included in email, telephone or fax communications on the "Jam Echelon Day". The trigger words include "hackers", "encryption", "espionage", "secret service", and "Bletchley Park". But Simon Davies, director of Privacy International, believes that sprinkling keywords within communications will not have an impact on the high-tech spy network. "The Echelon system works on a very sophisticated system of word relationships, rather than strictly on keywords," said Davies. "Powerful artificial intelligence software is used to judge the relationship between words, and analyse strings of words." Davies advises protestors to send a whole series of original keyword transmissions through email, rather than relying on someone else's template. "They will need to be imaginative and committed to take the original approach that could feasibly slow the system down, but the most important thing is to raise awareness about Echelon and the work of national security agencies." The existence of Echelon was confirmed by the European Parliament in May. A lengthy investigation found sufficient evidence to suggest that the spy system -- a US-led venture that has support from the UK, Canada, Australia and New Zealand -- is used for global industrial espionage, amongst other purposes. According to the report, Echelon has been capable of intercepting telecommunications messages to and from a particular person, via satellite, since 1978. They can see you... Find out how and why in ZDNet UK's Surveillance News Section. 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 other letters.