We have a site which is accessed entirely over HTTPS, but sometimes display external content which is HTTP (images from RSS feeds, mainly). The vast majority of our users are also stuck on IE6.

I would both of the following

• Prevent the IE warning message about insecure content
• Present something useful to users in place of the images that they can't otherwise see; if there was some JS I could run to figure out which images haven't been loaded and replace them with an image of ours instead that would be great.

I suspect that the first aim is simply not possible, but the second may be sufficient.

A worst case scenario is that I parse the RSS feeds when we import them, grab the images store them locally so that the users can access them that way, but it seems like a lot of pain for reasonably little gain.