California just gave its 40 million residents a permanent delete button for a largely covert part of the personal data economy.

On New Year’s Day, a government website opened to let Californians demand more than 500 intermediaries called data brokers wipe their personal information from the data on sale and regularly repeat those deletions in the future.

This deletion power is available only to California residents, and data brokers don’t have to comply until later this year. It’s still worth signing up for deletions now if you’re in California — and paying attention if you’re not.

So much of your personal information is amassed by so many companies that no individual can control the scope and the potential harm. Empowering yourself against rampant data surveillance requires savvy laws, regulation and enforcement that only governments can undertake.