Image
Looks like FireSheep add-on for Firefox is becoming hugely popular with tons of downloads and people reporting the efficacy of this niche utility. If you are speculating that Firesheep in the wrong hands can be a nemesis for you, then you definitely need to download and install FireShepherd.

This small application designed to render FireSheep useless by flooding the nearby network (especially Wi-Fi) with phony packets that shut down any suspected FireSheep programs running in the vicinity.
To download FireShepherd utility click here, optionally you can also download the source code for FireShepherd application in case you want to better it yourself.
Via: Notendur