I signed up to give it a try (mainly as a exercise for a class I was teaching on Personal Finance). They required access to my bank account, so I input the data. After working with the software enough to see whether it would be useful and something I'd recommend to my students, I deleted my account. A day later, I received an e-mail related to a transaction in the account to which]\Mint.com had access. I looked to make sure the account was deleted, and it was, however, they also allow 72 hours during which you can reopen the account. So, I wasn't too worried.
Now, two weeks later, I'm still receiving e-mail notifications about transactions in that account. They have no phone number nor e-mail address to contact them. My only choice was to change the password on that account. However, they apparently still have all my data and even after deleting the account, they are keeping my data.
DO NOT EVER TRUST MINT.COM. THEY WILL STEAL YOUR DATA AND NOT GIVE YOU ANY MEANS BY WHICH TO DEMAND THAT THEY DELETE IT FROM THEIR SERVERS.