Thread moved from Guides to "Other Security Related Discussions" since we don't want to provide a guide for people looking to crack into their neighbors wireless networks.
The video demonstrates that a wireless network that uses WEP and a poor password is highly insecure. WEP (Wired Equivalent Privacy) is flawed by design and easily cracked, as the video demonstrates. Use WPA or WPA2 with a strong pass-phrase to encrypt your wireless network.
Also WPS (Wi-Fi Protected Setup: is a computing standard that attempts to allow easy establishment of a secure wireless home network.) is susceptible to brute-force attacks even if you use WPA/WPA2 for encryption. If your router support WPS it is recommended to disable it and configure your network yourself and update the firmware on your router (or use DD-WRT alternative router firmware if your router supports it and you have necessary knowledge.). WPS is actually a bad implementation of otherwise good encryption algorithms. (Read more)
lifehacker made a blog post and a youtube video about Reaver, a linux tool used to crack WPS.