Mint doesn't ask for your CC number. Seems reckless and dangerous, not to mention daunting for the user.

By giving credentials AND cc numbers to a 3rd party (something credit card issuers say never to do), I'm in-effect condoning any actions that happen even if I don't make those actions.

Isn't it like handing the CC issuer a signed letter stating they need not worry about fraud protection, as I'm authorizing all transactions and will agree to cover them?

From an attack angle, now I have to trust that Datacoup will remain secure in all its interactions and that they will never suffer intrusions or decide to change their stance in the future (acquisition?).

I see nothing good coming of this request.