Firefox does not have this option, but is supposed to warn you about unencrypted content with https even if the page has some encrypted data.

Usually you won't have to worry that much about 'some unencrypted' data since most of the time they are images.

Thanks, vlad. But if this is the case, maybe Firefox should add this option. I've already seen https sites where not encrypted items were far more sensitive than simple images.

By the way, where can I contribute to a Fifefox wish list?

You can always file an enhancement request in Bugzilla (or more) - http://bugzilla.mozilla.org Try it out, I really encourage you to follow this path.

Thank you very much, vlad.

Best regards.

See also https://wiki.mozilla.org/Security:PresentationOfStates

Hi cor-el,

Thanks for the reference. I've browsed a lot of pages on related issues, but found no evidence that FF is doing it right to this day(!). What's the matter? Do you know when will we be able to block insecure content inside a should-be secure page?

A built-in mixed content blocker is planned for future release (see Security/Features/Mixed Content Blocker - MozillaWiki).