What about all the account login information you are providing. This must be stored somewhere. If hacked, couldn't this be used to log into the actual financial site and transfer out money, etc?
I like the idea but seems like there's a risk.
I would guess it's about the same risk as providing any financial institution login information - granted there's more in one place here. I had done a bit of research beforehand it they use the same type of security that banks use - here's one article (How safe are online financial sites like Mint.com? - USATODAY.com)
I haven't had any issues in nearly three years of using it and I imagine they take security pretty seriously, because if there were ever a breach, they'd lose all their users.