Apple is beefing up its do-not-track tool. The company's newest operating system, iOS10, will prevent ad networks and other third parties from using iPhones' and iPads' advertising identifiers -- unique alphanumeric strings -- to track users who turn on their devices' "limit ad tracking" setting.
The move will make it much harder for companies to collect cross-app data -- which can be used for ad targeting -- from people who activate Apple's "limit ad tracking" setting. As of this January, around 17% of mobile users (Apple as well as Android) had turned on their phones' limit-ad-tracking settings, according to research company Tune.
In the past, Apple's policies prohibited companies from serving ads based on data collected across apps to users who elected "limit ad tracking," but the company didn't technologically block outside companies from accessing the ad identifier.
Apple also previously allowed users to re-set their ad identifier -- the equivalent of deleting cookies on a personal computer. But the new setting gives people more powerful ways to prevent data collection, not simply delete identifiers after the fact. With the new configuration, the limit ad-tracking option "starts replicating the way cookie controls work," says Jules Polonetsky, CEO of the think tank Future of Privacy Forum. Polonetsky called attention on Twitter to Apple's new policy.
Of course, app developers and ad networks may be able to figure out ways to work around iOS10's technological block and track users regardless of whether they've turned on "limit ad tracking." But developers who do so run the risk of getting thrown out of the App Store.
This isn't the first time Apple has taken steps to prevent tracking. Consider, two years ago Apple said its operating system would put an end to location tracking by using “random, locally administered MAC addresses,” instead of the permanent MAC addresses. That move was significant because the retail analytics companies that track shoppers in stores do so via their devices' 12-digit “media access control” (MAC) addresses -- identifiers that are broadcast when users turn on WiFi or Bluetooth.
Apple's Safari browser also has long blocked ad networks' cookies by default. Some companies, including Google, famously found ways to hack Safari's default settings. But doing so resulted in lawsuits and, in Google's case, nearly $40 million in fines from the Federal Trade Commission and state attorneys general.