WarChucking is the name given by hackers and crackers to the new activity of vomiting copiously on the pavement to notify other hackers to the presence of open or potentially usable wireless networks in the vicinity.

Inspired by hobos of 1930s America who often left obscure chalk marking on sidewalks to alert others to locations where food and shelter were available, "WarChuckers" feel that what they're doing has a socially constructive edge and that they are not common criminals.

"Wi-fi networks are growing in popularity", an anonymous WarChucker told us before splattering the pavement with rotten fish entrails, apparently signifiying that a non-WEP-encrypted 802.11b diurnal network was operating in the area. With puke dripping from his bearded chin, he said that "some enlightened companies provide open nodes but many others lock their networks. But what's the problem with us tapping their bandwidth at night, say, when none of them are using it?"

Our hacker guide showed us some examples of the hidden signs encoded in WarChucked vomit - some decaying carrots and pasta remains on a kerbside indicated that password protection had yet to be enabled on a newly-installed wi-fi network, while a few streets away a lumpy mound of unidentifiable gastric waste covertly conveyed the pass-key required to access the Air Port network. "It's amazing how information-dense vomit can be", explained the WarChucker.

Yellow, decomposing stains on London's streets have long been a regular sight in the capital, but never before have they conveyed any information other than that some reveller took things slightly too far the previous evening. Now, computer rebels are sticking their fingers down their throats and spraying the brickwork with sodden stinking vomit in an underground conspiracy to democratise access to the information superhighway.