I don't see why this is such a big deal. Under the new healthcare laws, the IRS is going to be managing a vast majority of American healthcare records anyway. I think these agents were just being proactive!
Remember it's "theft" until you get someone to pass a law requiring people to voluntarily give you what you want.
the IRS is going to be managing a vast majority of American healthcare records anyway
For those interested, I found more info in the following links. Though, it still does not appear that the IRS would be privy to the exact details of medical care.
The only health-related records that the IRS will have under the ACA are information about what kind of a health insurance plan the taxpayer has. Under the law, people will be required to have a qualifying health insurance policy or pay a penalty to the government.
Remember it's "theft" until you get someone to pass a law requiring people to voluntarily give you what you want.