The issue was first noticed by e-Sushi, a well-known anonymous security researcher, and reported by theDaily Beast.
A form below the message asked for the users email password.
However, in a statement, Facebook said prompt was only seen by a small number of users.
They claimed it was meant to save people from an additional step while signing up for a Facebook account.
These passwords are not stored by Facebook.
The company also added that the process did not involve Facebook accessing peoples email inboxes.
source: www.techworm.net