With almost weekly news about databases being pilfered I am wondering why only passwords are hashed and not emails too? To be clear, I mean hashed with a static salt, which is stored somewhere other than the database.
Obviously, it's just one step among many. But as part of a multi-faceted security setup (ie - PDO, not rolling your own hasher, rate limiting, etc etc) why is it not more common to hash the email? Regarding logins (+ password reminder emails, etc) you could simply do a regular compare. Surely user emails should be treated more respectfully?
I have read a number of similar questions on SO / sister sites but am really unconvinced as to how this is not an idea that should be adopted more frequently?