In my last Diary[1], I shortly mentioned the need for correctly set Content Security Policy and/or the obsolete[2] X-Frame-Options HTTP security headers (not just) in order to prevent phishing pages, which overlay a fake login prompt over a legitimate website, from functioning correctly. Or, to be more specific, to prevent them from dynamically loading a legitimate page in an iframe under the fake login prompt, since this makes such phishing websites look much less like a legitimate login page and thus much less effective.