Definitely some new slants but most likely the same old scam. Some of the people have been arrested - but there seem to be enough people who have figured out the scam that they just pick up where the dead left off..
What does the postcard look like - pictures?
BTW: I am sure Carnival knows all about these scams - they are now extremely common. I guess they just can't do anything about them. They aren't the police, and it really isn't their fault or problem that these people are doing this.