Google’s auto-delete tools are practically worthless for privacy

By the time Google deletes your activity data, it’s already extracted most of the advertising value.

Google’s auto-delete tools are practically worthless for privacy
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By default, Google collects a vast amount of data on users’ behavior, including a lifelong record of web searches, locations, and YouTube views.


But amid a privacy backlash and ongoing regulatory threats, the company has started to hype its recently released privacy tools, like the ability to automatically delete some of the data it collects about you—data that helps power its $116 billion ad business.

With a trip to Google’s activity controls page, you can choose to purge that data on a rolling three-month or 18-month basis. The company pitches this tool, along with the ability to manually delete data through Google’s activity pages, as one of many ways users can control their privacy.

“You should always be able to manage your data in a way that works best for you—and we’re committed to giving you the best controls to make that happen,” two Google product managers wrote on the company’s blog in May.

[Animation: Google]
In reality, these auto-delete tools accomplish little for users, even as they generate positive PR for Google. Experts say that by the time three months rolls around, Google has already extracted nearly all the potential value from users’ data, and from an advertising standpoint, data becomes practically worthless when it’s more than a few months old.

“Anything up to one month is extremely valuable,” says David Dweck, the head of paid search at digital ad firm WPromote. “Anything beyond one month, we probably weren’t going to target you anyway.”


More recent, more value

Dweck says that in the digital ad industry, recent activity is essential. If you start searching on Google for real estate or looking up housing values, for instance, Google might lump you into a “prospective home buyers” category for advertisers. That information becomes instantly valuable to realtors, appraisers, and lenders for ad targeting, and it could remain valuable for a while as other companies, such as painters or appliance brands, try to follow up on your home buying.

Still, it’s unusual for advertisers to target users based on their activity from months earlier, Dweck says. There are exceptions—for example, he cites a TV network targeting baseball fans for playoff ads if they were active on Twitter in past seasons—but they’re rare.

“I feel like them auto-scrubbing data every three months is really lip service,” Dweck says. “It’s not some massive change, because the reality is that no one was really buying that data.”

Besides, Dweck says, deleting data from Google doesn’t stop advertisers from tracking you on their own. If you search for shoes on Google, and in the process click through to a shoe brand’s website, you’re now being tracked by that brand regardless of whether Google purges its own data. That tracking would likely be associated with whatever device you use, so it’ll stick until you buy a new phone or computer.

“Once you’ve taken an action on an advertiser’s website, for us that 90-day window doesn’t matter,” Dweck says.


Why not discard data sooner?

A Google spokesperson would only say that its research showed a preference among users for three-month and 18-month windows, noting that they cover an entire season or multiple seasons of data respectively. The spokesperson also says Google is open to feedback and may fine-tune its time frames in the future. It’s also worth noting that Google still lets users delete all of their activity data manually, though this requires visiting three separate pages for web and search, YouTube, and location history.

Jeremy Tillman, the president and head of product and marketing for the anti-tracking extension Ghostery, doesn’t buy the argument that users only want to delete data on a seasonal basis. He believes Google should offer much shorter auto-delete windows, or provide an option not to retain any activity data.

“To the extent that they do anything, I think it’s more for the PR and to give them a credible defense when they come under scrutiny,” he says. “There’s no way they would do anything meaningful because it would threaten their underlying business model.”

Dweck says that even just 24 hours of activity data is extremely valuable to advertisers. Still, he acknowledges that a daily auto-delete window would significantly affect advertisers’ ability to target Google users based on a profile of their search activity.

“If we hadn’t captured you in that first 24 hours, we’re not going to know what your intent was,” he says. “If they scrubbed after 24 hours, it would be a huge impact on us, because we wouldn’t be able to target you beyond that short window of time.”


A three-month precedent

The auto-delete windows established by Google may be setting a precedent for the tech industry. Last month, Amazon announced its own auto-deletion tool for recordings of Alexa voice commands, using the same three-month and 18-month options that Google debuted earlier this year. (Like Google, Amazon also lets users delete their full history manually, through its website or the Alexa app.)

An Amazon spokesperson said the company chose these time frames so users could review their own activity, arguing that parents might want to look up their kids’ Alexa commands and that customers might want to consult their voice history while troubleshooting.

“We think the opportunity to review voice recordings is an important privacy control, because it gives customers transparency over how they and others are interacting with their devices,” the spokesperson said in an email statement.

Unlike Google, Amazon does not directly use Alexa activity for ad targeting. But if you use Alexa to shop on Amazon or interact with other Amazon services, that activity could in turn affect the recommendations that the company shows elsewhere. Amazon retains that data even after you delete the associated Alexa recordings, and there’s no way to delete it automatically.

Longer retention windows aren’t just motivated by targeted ads. They also give tech giants more time to train their machine learning models on users’ data. That in itself has become a privacy concern, as Amazon, Google, and others have faced a backlash for having humans review voice assistant recordings for accuracy.


Amazon acknowledges that by keeping Alexa activity for longer, it enjoys more time to train its machine learning models.

“Customers expect Alexa will improve over time, and training Alexa with real-world requests from a diverse range of customers helps Alexa respond properly to the variation in our customers’ speech patterns, dialects, accents, and vocabulary,” the company says.

That’s great for Amazon and may arguably even benefit users, but it doesn’t explain why users don’t have an option to automatically delete their activity sooner if they wish. Both Amazon and Google are offering a veneer of control—just enough, perhaps, to fend off strict regulations akin to Europe’s GDPR law—but they’re unwilling to give up anything that might affect how they do business. That kind of law, Dweck says, might be the only way to really protect users’ privacy in the end.

“Most of the privacy stuff I’ve seen from Facebook, Google, Amazon, anyone who’s tried to shed light that they’re not as invasive, it’s usually done to give the appearance that they’re doing what’s right by consumers and by their users,” he says, “versus what’s actually right for privacy.”