They can mostly be handled, as I discovered when creating a Chrome plug-in with a similar interface: https://chrome.google.com/webstore/detail/beoobakjmicjpifdp

They can mostly be handled, as I discovered when creating a Chrome plug-in with a similar interface: https://chrome.google.com/webstore/detail/beoobakjmicjpifdpcbfdgifhimhpnen https://chrome.google.com/webstore/detail/beoobakjmicjpifdpc... It's sites like github, which use X-Frame-Options, that can't be displayed in a iframe.