Facebook dip
You're on Facebook, and some annoying person who always messages you signs in. You log out right away before they can bother you with another stupid message.
He was on Facebook, saw his boss signed in, and logged out before he got yelled at.
She saw her annoying friend signed in and logged out before he could message her again.
He checked Facebook, saw his ex was online, and logged out before she could send another message.