JavaScript
From Hackepedia
Turn it off in my browser
Javascript should only be enabled on websites that you trust. Along with Flash, malicious javascript is often used to compromise your browser, and as a result, your computer.
To turn Javascript on or off:
Chrome: Options -> Under The Hood -> Content Settings
Firefox: Under Options/Preferences -> Content You might also want to check out the Firefox NoScript plugin.
Opera: Preferences -> Advanced -> Content