Scary enough to the average user it'd probably kill the the technique very quickly.
I'm not sure about that. It's nothing that desktop clients such as Thunderbird haven't been doing for years. I don't see any remote images in any e-mail until I click to say load them, and this works in much the same way that plug-in elements like Flash and Java are now click-to-show in various browsers. Numerous marketers and mailing list services still use the technique to track an approximation of reader numbers, though.
I'm not sure about that. It's nothing that desktop clients such as Thunderbird haven't been doing for years. I don't see any remote images in any e-mail until I click to say load them, and this works in much the same way that plug-in elements like Flash and Java are now click-to-show in various browsers. Numerous marketers and mailing list services still use the technique to track an approximation of reader numbers, though.