[Attack] Cross Site Framing (Clickjacking) [Responsibility of] Page Owner [Prevention] JavaScript frame busting, X-Frame-Options, NoScript [Future Standards] X-Frame-Options, Content Security Policy [Future Responsibility of] Server Owner [Example] 
Site A loads site B in an iframe, making it look like part of site A. Site A then tricks the user to click on the iframe, thus using the user's credentials to perform actions at site B.