I was curious about this exact thing when I saw they hashed a phone number (of all the easy to guess things). Yes a Salt makes it improbably to rainbow table...

I was curious about this exact thing when I saw they hashed a phone number (of all the easy to guess things). Yes a Salt makes it improbably to rainbow table... but if their database ever gets leaked then everyone is toast. It'll only take, as you said, seconds per account to brute force once the salt is exposed.