US law firm PCVA has filed an application for a class action lawsuit on behalf of angry iPhone owners affected by an Apple software update that bricks devices if Touch ID has been repaired by an unapproved dealer.
The firm signalled last week, in the wake of the so-called 'Error 53' controversy, that it was exploring a class action suit against Apple over the issue.
On Thursday, PCVA filed an application in the District Court for the Northern District of California, seeking relief on behalf of several affected iPhone 6 owners.
If an iPhone 6's Touch ID fingerprint sensor has been replaced by a non-Apple approved repair shop, the device becomes unusable and displays an 'Error 53' message, advising them to contact Apple support.
Apple has explained that Error 53 is a security measure, since Touch ID is a sensitive component linked to Apple Pay.
"iOS checks that the Touch ID sensor in your iPhone or iPad correctly matches your device's other components. If iOS finds a mismatch, the check fails and Touch ID, including for Apple Pay use, is disabled," Apple said.
iPhones with Touch ID store fingerprint data in what Apple calls a "secure enclave" that is paired to Touch ID's sensor.
The suit is seeking an order that would force Apple to stop disabling iPhones that have been repaired by a third-party and provide a software update that restores functionality to them.
It also wants Apple to foot the bill for repairing complainants' devices under warranty. According to the complaint, Apple has declined to repair devices under warranty since it was a problem caused by the consumer using a non-approved repair service.
PCVA accuses Apple of exploiting the "cult-like following" it enjoys and argues the class action should proceed on the basis that damages affecting thousands of iPhones exceed $5m.
"As is invariably true of power and control, too much of a good thing becomes problematic and, even, abusive. Apple's Error 53 code, for which this lawsuit seeks redress, represents Apple's control over the product gone too far," the complaint reads.
The plaintiffs include Nicholas Lusson, Bryant Kushmick, Alexander Saenz, John DeNoma, and Nora Penner.
While the suit focuses on Error 53, it also more broadly criticises Apple for charging higher prices than third parties to repair components and, in some instances, for refusing to repair cheap components.
Additionally, it says that Apple should have warned owners that using an unapproved repair service could trigger Error 53.
The other concern raised is that owners cannot extract any data stored on devices with Error 53.
ZDNet has sought comment from Apple and will update the story if it receives a response.