• by Wendy Davis  @wendyndavis, December 11, 2023

California's privacy agency is calling for state legislation that would require browser developers to offer a tool like the Global Privacy Control, which aims to allow consumers to opt out of online behavioral advertising throughout the web.

“If approved through the California legislative process, this proposal will not only advance Californians’ consumer privacy, but help incentivize the development of privacy-enhancing technologies,” Ashkan Soltani, executive director of the California Privacy Protection Agency, stated Monday.

Late last week, the agency voted 5-0 to find a potential bill sponsor and work with that person on crafting legislation that would require browsers to include opt-out preference signals. The best known current opt-out preference signal is the Global Privacy Control -- a mechanism created by privacy advocates to enable consumers to reject all sharing of online data for ad purposes, instead of having to opt out of behavioral targeting company-by-company.

California's privacy law gives consumers the right to reject “cross-context” behavioral advertising -- meaning ads served based on activity across different sites. That law also has been interpreted as requiring companies to honor universal opt-out requests, referred to in the regulations as opt-out preference signals.

Other states including Colorado, Connecticut, Delaware, Montana and Texas have recently passed laws or regulations mandating that companies honor universal opt-out mechanisms.

Currently, developers including Mozilla, Brave and Duck Duck Go build the Global Privacy Control into their browsers.

Google's Chrome doesn't include the specific “Global Privacy Control,” but has long had a “do-not-track” setting, which sends a no-tracking request to all websites consumers visit. The California privacy agency suggested Monday that this older “do-not-track” command isn't equivalent to an "opt-out preference signal," but it's not clear whether other state officials will agree -- or whether Google could tweak the do-not-track command so that it could serve as an opt-out preference signal.

Apple used to include a “do-not-track” setting in Safari, but discontinued the setting a few years ago due to concerns that ad-tech companies would harness the signal for device fingerprinting -- a tracking technique that identifies users based on on characteristics of their browsers.