[dba-Tech] Drop down list of usernames on facebook

Hello List,

A few weeks back, when using my main PC and when using Chrome, and when
logging into facebook, I noticed a second username in addition to my
facebook username.

I could see my name and a second email address of a friend that I sometimes
interact with over email.  He is definitely not a hacker so I just ignored
it and assumed that perhaps I had accidentally pasted into that box at some
stage when I had his email address in my clipboard.  I was surprised
however, because I have little interaction with him.  I watched it over the
following days with some curiosity / concern i.e. "Why is Nialls email
address in the login text box on my Chrome"

Well, a few days ago that drop down list changed from two names to five
names including my own.  Two of the email addresses, I never heard of and
cannot find when I search for them in my Gmail.

*Summary:*
When I click the login control on facebook, I see four names that should
never be logging into facebook on my PC.  One guy lives in Korea!

Any thoughts ?

Hope your 2013 is great,

Mark