The suit alleges that Apple improperly collected data on the locations of customers via iPhones.
Apple may face severe penalties in an ongoing privacy case, filed in 2011,over its document-sharing practices in court.
The suit alleges that Apple improperly collected data on the locations of customers via iPhones, even after the user choose to opt out of it.
According to Bloomberg, US Magistrate Judge Paul Grewal said that Apple's document production has more than doubled since the court got involved in policing information-sharing obligations.
"We've gone through close to a dozen people that should've come up and didn't come up" in original requests for information," Grewal said.
"In light of that process, how am I to have any confidence that the procedure now is any better than it was initially?", Grewal asked.
Bloomberg reported that Grewal told Apple on 6 March to submit a detailed account of how it collects and evaluates documents given to plaintiffs' counsel.
Apple has produced over 2,000 additional documents since the order.
Recently, a US district judge dismissed a motion from Apple by ruling that she was disturbed by the company's attempt to throw out the case as it failed to provide the required documents to plaintiffs' counsel.