"If you are using an iFrame to display a site that isn't yours, even for legitimate purposes, you have no control over that content—it can change at any time," Simmons warns. "One day instead of looking into an iFrame, you might be looking at an entirely different kind of portal."
Holy shit this guy is amazing.
I get it though. People trying to monetize your work which was purposely hosted for free without ads would drive me mad too.