In context: Apple seems to have no shortage of antitrust accusations flung at it lately. Earlier this week, the UK's Competition Appeal Tribunal dropped a case against the Cupertino tech titan brought on by the continuing "Apple Tax" spat with Epic Games. Now, the company faces scrutiny in the US from the Department of Justice over its alternative sign-in method.

The Information reports that developers began complaining last summer about being forced to use the "Sign in with Apple" (SIWA) feature in their apps if they employed other third-party authentication measures like signing in with Facebook, LinkedIn, or Google. The DoJ is interested in finding out if the button gives Apple an unfair advantage by making it more difficult for consumers to switch to rival devices.

According to sources close to the DoJ, some developers using sign-in buttons for Facebook or Google have done away with them because they did not want to be forced to add the Apple authentication method. The primary reason for not wanting to use SIWA: it's too private.

"Representatives of two iPhone app developers that complained to DOJ investigators about Apple's requirements told The Information that after Apple made its sign-in button mandatory, they removed all sign-in buttons from their app because they didn't want to include Apple's and potentially lose out on gaining information about their customers."

With the Sign in with Apple button, the only information the developer can access is the user name and email associated with the iCloud account. A unique stable anonymous token is then produced for future authentications. Users may also opt to hide their email addresses when clicking the button for the first time (above). In this case, SIWA creates a random email that routes to the associated iCloud address.

By contrast, developers can access much more information when using Facebook's and Google's authentication methods, including birthdates, hometowns, contacts, and more. For example, take a look at all the user information that Facebook may allow apps to ask for on their Permissions Reference webpage.

It's somewhat important to note that apps that do not use a third-party authentication button are not required to use SIWA. Only those using these methods have to also include Apple's. This requirement seems to make sense since Apple is merely trying to ensure that users have the option to remain private. However, developers see it as the company once again throwing its weight around to stifle competition. We'll have to see what the DoJ has to say about it when it concludes its investigation.

Image credit: Kenny Wassus