WEP also known as Wired Equivalent Privacy was intended to provide comparable confidentiality to a traditional wired network. Several security weaknesses have been identified. Despite the weaknesses, WEP provides a level of security that can deter casual snooping.
The FBI method relies on the following tools: Kismet and Aircrack. Both can be found on Linux live cds such as knoppix.
Do the following if you have the tools available: