Being framed can also expose you to clickjacking attacks. (http://en.wikipedia.org/wiki/Clickjacking http://en.wikipedia.org/wiki/Clickjacking) If your site is

Being framed can also expose you to clickjacking attacks. (http://en.wikipedia.org/wiki/Clickjacking http://en.wikipedia.org/wiki/Clickjacking) If your site is mostly read-only then clickjacking doesn't really matter. But it's good practice to break frames around your site if you care about your visitor's clicks being spoofed (i.e. if you're running any sort of web application). Twitter started doing this after they got hit by clickjacking a while ago: http://blog.twitter.com/2009/02/clickjacking-blocked.html http://blog.twitter.com/2009/02/clickjacking-blocked.html