I'm looking at some legacy code and see the following media query:
@media (min-width: 768px) and (min-width: 768px) and (min-width: 768px)
I'm guessing this is either an authoring mistake, or the result of a misconfigured preprocessor or a preprocessor bug. If this was a deliberate workaround for some kind of browser bug or something (IE? Safari? Chrome?), it hasn't been documented anywhere on the web.
This statement is equivalent to
@media (min-width: 768px)
(but if you're familiar with the standard, you probably already guessed as much)