[hollerith]

Yahoo did something very much like that about 5 or 6 years ago: inviting me to upload an image file, then telling me to make sure the image is present every time I log in.

I upload an image file; the next time I found myself at Yahoo's login prompt, the image file was there; the time after that, it was absent. It has not re-appeared since.

Just offering a data point: I don't know enough to have an opinion about the technique.

[itistoday2]

I think he was making a joke. Those pictures do nothing to prevent TLS MITM attacks.

[gburt]

I thought about this for a second, and what it does do is take an "offline" phishing attack and make it an "online" phishing attack that presumably has logs and can be throttled.