You've discovered another website framing your content, leaving an extra panel of theirs (along with their advertising and identity) that you never intended to be seen alongside your site. You might be tempted to call your attorney, file a "cease and desist" lawsuit or send some nasty email to that other webmaster. It is infringing on your copyrights, isn't it?
When other sites frame your website without permission, it raises some sticky questions that copyright law hasn't quite gotten around to dealing with yet. The good news is that you don't need any court's permission to make that foreign frame slide right off your site. It is, after all, your server.
