[Firehed]

No, it does not. Here's a sample:

  function checkPassword($user, $posted_password) {
    return bcrypt(strtolower($posted_password), $user->saved_hashed_password) === $user->saved_hashed_password;
  }
  function setPassword($user, $posted_password) {
    $user->saved_hashed_password = bcrypt(strtolower($posted_password), generateSalt());
  }

Lowercasing the password before hashing (both on save and check) indeed lowers the strength of the password, but it saves a lot of support headache from users that have caps lock turned on, or your mobile device auto-capitalizes the first letter. Facebook does this, although in a better way: http://www.zdnet.com/blog/facebook/facebook-passwords-are-no...

While we can't know without looking at their implementation, it's certainly possible and indeed fairly easy to build a forgiving system without having the password stored in a reversible format.

[Piskvorrr]

Hmm, this would indeed be a simple, yet non-catastrophic explanation (and useful UX to boot). That would make sense; and if this were the case, I'd be glad I was wrong.