We're all going to have to design with unexpected problems in mind. Some people use frames so they can steal your page content, which is also a problem. You never know who is linking to your site and accidentally, or intentionally, trapping your site within a frame so it's a good idea to use some type of frame security. Here's a small JavaScript that will knock off any unwanted frames when entering your website.
Lets examine the code.
Parent refers to the parent document, and what it does is test to see if the parent has the same name as the self document. If it doesn't have the same name then the page is reloaded without the frames. Really simple and effective.