This HOWTO has instructions to build your own Newstweek device, a small innocuous wallplug allowing you to remotely manipulate news read by other people on wireless networks. If you want to learn more about Newstweek, click here.
The version you’ll be building uses low-cost (and low-power) hardware, capable of fitting into a small plastic enclosure; power transformer and all. This version is not suitable for modifying data on large LANs, rather small LANs with moderate traffic of up to 5 client machines (including tablets and smartphones).
Information subversion is the future 🙂