If someone gives me the credentials to login to a streaming site they have an account for, would it be illegal for me to share the credentials with someone else? 

For example, if Joe tells me the username and password so I can watch Netflix on his account, would it be illegal for me to share it with Bob? Would it make a difference if I created a separate account for Bob (but still under Joe's subscription)? 

**Assume there is nothing in the terms of service prohibiting accounts from being shared**. To my understanding, this comes down to if the license Joe granted me is sub-licensable or transferable. I heard it often depends on if the license was paid for or free. I'm asking this question to learn about the law, obviously the best course of action would be to ask the owner if it's ok to share.