This add-on protects you from phishing or scams (through XSS injection attacks) while you’re on Facebook – Version 4.2 introduces a Tracking Protection feature as well. This add-on is designed to protect you against them. Facebook Phishing Protector will warn you when an unusual activity is detected, such as a script injection attempt or a website other than Facebook requesting your credentials.
Here are a few more details about the Facebook Phishing Protector:
The latest version introduces a Tracking Protection feature which when enabled will protect your privacy by blocking Facebook scripts while you are not in their website. This will forbid Like buttons and such from being run on 3rd part websites. Please note that to be able to analyze/study a certain script injection we need the exact details of what is being blocked and where. While you can just copy and paste what is said on the inline popup, we prefer the more helpful information which is being logged into the Firefox’s Error Console (You can open it using CTRL+Shift+J) – In the other hand, if you aren’t using Inline Popups but rather Firefox’s Notification Popups the Error Console will be opened by clicking the “Details” button.
Want to learn more? You can pick up the Facebook Phishing Protector from the Firefox Add-ons website.