The most popular social networking site http://facebook.com has some facetiousness to its email or phone and subsequently password section. We are keen on the latter part.
After entering the email or phone, you enter the password. There are two possible inputs which are termed as valid. [Intriguing]
You can either input your password as it is or you can just reverse the case of all the alphabets in your password i.e lower to upper and vice versa. (The numbers and allowed special characters are kept as they are).
For example if your password is QUoraN1@, then input quORAn1@ and voila, 69 new notifications;10 messages;23 requests blah.
This feature was added designedly. We tend to keep our caps lock key on and struggle logging in, so Mark Zuckerberg and team accounted for the same.
This is not a loophole. If you do not believe, give it a try.