[tsimionescu]

> In my experience a lot of people actually do think that it's case sensitive.

I don't think they really do. They may think case matters somehow, and so may be careful to reproduce the exact case that they used before, but I don't think many people would expect [e-mail] and [e-mail] to be too different email accounts.

[ghaff]

In the general population, how many people do you think understand that username (including an email address) probably isn't case sensitive but that password almost certainly is?