A group of wealthy donors wanted to give millions to two right-wing California political campaigns last year, but didn’t want anyone to know their identities. They came up with a scheme that any money-launderer would be proud of, funneling the cash through a convoluted series of independent spending groups that were allowed to collect unlimited dollars. By the time the donations had been used to buy advertising, the original money trail had been erased.

Or so they thought. California has one of the best laws in the country requiring disclosure of political donations, and officials at the state’s Fair Political Practices Commission suspected that the bulk contributions were obscuring the true donor groups. A yearlong investigation revealed the nature of the scheme, and the groups were accused of violating state law.

A few days ago, as part of a civil settlement, the state imposed $16 million in penalties and fines on the groups, a record in a campaign finance case. Though it’s not clear how much of those penalties will ever be collected, or even who many of the original donors were, the effort demonstrates the importance of state disclosure laws and aggressive enforcement, particularly since Congress has refused to pay attention to abuses on a national level.

The California commission, in fact, has done the political world a favor by exposing the secretive network of conservative groups that have aggressively taken advantage of the unlimited donations allowed by the Supreme Court, as well as the ability to hide donors that is permitted by the Federal Election Commission and lower courts. The network centers on groups with close ties to the Koch brothers, whose huge donations have played such a large role in electing Tea Party candidates around the country.