Firesheep is a Firefox add-on that allows anyone to hijack other people’s social network accounts in open wifi zones. I'm not sure of the legalities of this is the US since state laws differ from state to state. I think cali has sticked laws on this. I think in the UK u can get into some legal trouble with their cyber security council thing.
This thing is extremely easy to use. Just head into a wifi populated area and boom your in peoples business like crazy. I need to look up the laws on this because you can do some serious damage to people using this extension. The possibility of the amount of PII you will be collecting on people is scary. Whats even scarier is that people are more then likely doing it to you now since this craze has spread like wildfire.
Use of this addon IS illegal outside of private use to test network security.
The program was originally created to get people aware of the insecure login credentials on social networks. It has done its job very well and is out of control.
Tomorrow i will post a program for anyone in a public wifi area to use that will keep you and people around you safe from someone looking at your private information.
When logging into a website you usually start by submitting your username and password. The server then checks to see if an account matching this information exists and if so, replies back to you with a "cookie" which is used by your browser for all subsequent requests.