It’s hard to believe, but Eric Holder’s Justice Department has actually done a good thing. On Friday, the attorney general barred state and local police from using federal law to seize property from citizens without a warrant or criminal charges. Under a program called Equitable Sharing, police could pull someone over for some minor infraction, and then, if they found, say, a large amount of cash, seize it and the vehicle without any evidence that the cash had been obtained illegally. The citizen would then have to prove his innocence to get it back.

This was no small business. Since 2008 there have been more than 55,000 seizures under this program, worth $3 billion. The proceeds were usually split 80-20 between the local police and a federal agency.

The program originated in the early 1980s as a way of attacking the illegal drug trade, which is largely conducted in cash. After 9/11 it was ramped up to fight terrorism.

Abuses were sure to follow, and they did. After all, if a local police department can substantially increase its revenues by seizing property and making the owners fight (at their own expense) to get it back, and they can then use that revenue to increase expenditure, that’s a tremendous motivation not to be over-scrupulous.

As a general principle, government departments should be funded solely by legislative appropriations. Doing otherwise, as in this case, produces an open invitation to corruption, which will all too often be accepted. In other instances, such as funding wildlife and environmental agencies out of hunting license fees, policy is skewed in order to maximize income.