Here’s a Firefox extension called Firesheep that lets you (easily) hijack Facebook, Twitter sessions of other people on public wifi networks.
Protect yourself!! Read the article, be informed. Use the “HTTPS Everywhere” add-on from EFF to prevent your social networking identities from being comprimised.
Special thanks to Eric Butler for exposing these facts through the developement of Firesheep, and nudging (lazy) website admins to take a closer look at protecting their users’ privacy.