Eric Butler created Firesheep extension for Firefox with an altruistic aim to point out the negligence of popular web services that follow weaker security measures. This Firesheep extension basically exploits the HTTP session hijacking over an open wireless network. Once the user logs in to an encrypted login providing website, the cookie rests on the user's computer. This cookie is not encrypted and vulnerable. With HTTP session hijacking method, an attacker can grab that cookie carrying account information.

Firesheep snoops around in open Wi-Fi networks and so it's your responsibility to make your Wi-Fi network more secured as well as password protected. Butler stated that the vulnerability always existed since sophisticated hackers have exploited it. Hence now with Firesheep, an average Internet user can understand the importance of secured websites and compel several websites to strengthen their security.