Exposing the timing here can only tell you one thing: the password that you're trying works for Facebook, but the capitalization might be wrong if you're using

Exposing the timing here can only tell you one thing: the password that you're trying works for Facebook, but the capitalization might be wrong if you're using it to get into the user's account on another site. But since there are only three variants on the password, it gives you effectively nothing. This would be insanely difficult to pull off (many, many login samples) for absolutely no payoff; they might as well save the extra hashes if it works the first time.