WiFi sniffing is EASY to do, it is commonly done, and the real question is at what point will someone do real damage by using what they sniff, and when will this be brought to the public's eye by the courts or by congress?
Think about it. How long will it take before someone starts methodically wardriving in front of major politicians' or executives' homes, looking for open access points and sniffing interesting traffic by sitting in their car across the street each evening? Don't you think it's already happening? [Privacy Digest]