Tether claims on its main webpage to be 1:1 backed by "by traditional currency held in our reserves. So 1 USD₮ is always equivalent to 1 USD." If they are real

Tether claims on its main webpage to be 1:1 backed by "by traditional currency held in our reserves. So 1 USD₮ is always equivalent to 1 USD." If they are really just "backing" it with bitcoin then it is fraud.