Apple wants its devices to know everything about you. But more than ever, it wants you to know that Apple doesn't know what those devices know.

In its Worldwide Developers Conference Monday, Apple execs seemed to emphasize—perhaps more clearly than in any previous keynote—that the company wants to store the personal data its devices silently gather locally, rather than upload it to the cloud. And that privacy-focused marketing continues a push from Cupertino to differentiate itself from Google, Microsoft, and other competitors whose ad-based business models require broader data collection.

In the iOS-focused segment of the event, Apple software engineering VP Craig Federighi detailed how Apple's mobile operating system now collects myriad data about a user's activity to make Siri into a more "proactive" assistant and add "context" to your commands. Plug your headphones in to begin your morning at the gym, and iOS will remember your exercise schedule to offer up workout music; receive a call from an unknown number, and it will mine your communications to offer a guess at who's calling.

But Federighi took special pains to emphasize that almost all that personal information is kept on the iPhone or iPad, not sent to Apple's servers. And when it does upload user data—Federighi gave the example of traffic data in Apple Maps collected from users' phones—it's "anonymous" and not tied to the user's Apple ID. "We don't want to know," Federighi said, to some of the loudest applause of his speech. "All of this is on device, and it stays on device under your control.”

"Thank you!" shouted one developer in the audience.

In another segment of the event on Apple's new "News" service, Federighi returned to that privacy point, emphasizing that "unlike any other news aggregation," News in iOS doesn't upload your reading habits, and is "designed from the ground up with your privacy in mind."

Apple

Despite that new privacy marketing push, Apple's track record is hardly spotless. Last year the company took flak from privacy advocates when it was revealed that its Spotlight search tool shares user queries and even location data to Apple's servers, albeit tied to a temporary user ID. And a much larger privacy scandal rocked the company in September of last year when hackers revealed collections of nude celebrity photos they'd pulled from iCloud backups—in many cases, users didn't even know their photos had been uploaded to the cloud by default. Apple responded by strengthening two-factor authentication for iOS backups.

You’re in control of your data. Searches are not associated with your Apple ID and not shared with third parties.

But increasingly, minimizing data collection has become "part of [Apple's] design process" and internal guidelines, says Rich Mogull, a security industry analyst who closely follows the company. He says the change has been years in the making, but accelerated with Edward Snowden's revelations of NSA surveillance. Internal NSA documents revealed by the German magazine Der Spiegel even mocked Steve Jobs as "Big Brother" and referred to Apple users as "zombies."

"It’s a competitive advantage. As privacy becomes something people care about, this gives Apple an advantage over Google and Microsoft, companies that sell collected data," says Mogull. "Their business model gives them a flexibility the other companies don’t have."

Apple's most dramatic privacy stance, in direct contradiction to the US government's wishes, has been to strongly encrypt the storage of iPhones and iPads by default. That move has even drawn direct criticism from FBI director James Comey. But Apple CEO Tim Cook has held firm.

"We don’t just grab everything, so we’re not the richest target for those who want access to that kind of data," Tim Cook said in a recent speech at a dinner organized by the Electronic Privacy Information Center. "And for encryption—well we’re continuing to do the right thing, and we are moving forward. In an era where our information is digital, portable and sought-after more than ever, we want to build products that keep people’s information safe.”

On that encryption front, Mogull argues that the company's decision to keep users' data tightly locked has as much to do with the values of Apple's executive team as it does with marketing. "They didn’t need to make the iPhone so heavily encrypted. They could have caved to the government and it wouldn’t have dramatically affected sales," says Mogull. "But they’ve put a stake in the ground."