Yeah, part of the nice/scary thing about HSTS is that it is a highly persistent cache. The browser is reluctant to clear it because it's a security feature. So

Yeah, part of the nice/scary thing about HSTS is that it is a highly persistent cache. The browser is reluctant to clear it because it's a security feature. So HSTS pins can be stored for up to a year in FF/Chrome, even if you are deleting cookies regularly.