The measure could make it clear to consumers that do-not-track commands are largely meaningless, as things stand today.
Browser manufacturers began rolling out do-not-track headers several years ago, in hopes of offering consumers a way to simply and universally opt out of tracking by publishers and ad networks. The headers themselves don't actually block tracking. Instead, they send a do-not-track request to publishers and ad networks, which those companies can -- and often do -- ignore.
For the last two years, advocates, computer scientists and industry representatives in the World Wide Web Consortium's tracking protection group have been trying to figure out how to interpret the headers. But the group has reached a standstill, with privacy advocates and industry representatives unable to resolve their disagreements.
As of today, a handful of Web companies have said they will honor the headers, but many ad networks and publishers say they are holding off on many promises until the W3C sets some sort of standard.
This potential California law wouldn't change that, because it would only require some Web companies to state how they respond to the headers. The bill also would only apply to a limited group of Web companies -- those that collect personally identifiable information from consumers.
But even though the measure won't necessarily prompt any company to change its data collection practices, it still could embarrass some site operators by forcing them to admit that they ignore the requests.