When I posted about Conference Wifi I said When people create and share networks from their Powerbooks, it causes collisions that interfere with everyone's access. Turns out I am wrong, Macs are the victims here, as Kevin Marks pointed out:
The more common problem at conferences is Windows users accidentally creating private networks with the same SSID as the public one, causing routing failures, The Mac Airport software will not allow this to happen, unless you explicitly over-ride a lot of options.
Asked Nikolaj from Organic Network, he said Kevin was right and they create the disruption for the mac powerbooks, as the powerbooks will often default to the p-2-p (adhoc) network rather than the infrastructure (ap). Kevin pointed out this was Apple following the spec and it assumes all senders with the same SSID are part of the same network, so they choose the one with the strongest signal.
Meanwhile, Jeremy's Trash Talking idea has progressed and someone has even started coding it. Seems the app for Macs would be to signal to them why their wifi won't work. Perhaps being a friendly informant is more constructive than vigilantism. It could also suggest ripping the PCMIA card out of their neighbor's PC, if it felt nasty.
Kevin suggested: The real tool you need is one that finds the rogue Windows AP box and sends it a popup message to stop it. Lazyweb? This is a real big problem for even less than big groups and I hope someone solves it.