I have a minor concern and a major annoyance with the feature that tries to help us put in addresses or usernames, etc.
I once kept typing without hitting the Tab key, and ran a password onto the end of my user name on a particular site.
So, now, when I (or God forbid someone else) even punches in the first letter of my username, that one displaying my password is also offered as a choice, as well as any versions I misspelled along the way.
Well, it's easy enough to change my password, as I try to do anyway, but it got me wondering how to clear that clutter.