I see every now and then how hackers stole DB with emails and hashed passwords of millions of users from popular websites and sell it on the black market.
I assume that passwords were hashed with proper unique salt for each which makes rainbow tables useless. And in the end, a consumer only gets emails and useless hashes.
My question is, how it can be useful for anyone? The only possible reason as far as I can see is that they also provide salt for each password. Is my assumption correct?