Here's someone who discovered his neigbors were using his wireless Internet connection without his bidding. Instead of blocking them he decided to have a little fun, first redirecting all of their web page access to Kitten War, then he set up a web proxy so that he could manipulate what they were seeing, to interesting effect. Full details, including source code and configuration, are available.

• http://www.ex-parrot.com/~pete/upside-down-ternet.html