Each person in the suit is seeking 1 million won ($932) in damages, Kim Hyeong-seok, one of their attorneys, said Wednesday. He said they are targeting Apple Inc. and its South Korean unit to "protect privacy" rights.
Apple has faced complaints and criticisms since it said in April that its iPhones were storing locations of nearby cellphone towers and Wi-Fi hot spots for up to a year. Such data can be used to create a rough map of the device owner's movements.
Apple also revealed that a software bug caused iPhones to continue to send anonymous location data to the company's servers even when location services on the device were turned off.
The company has said it will no longer store the data on phones for more than seven days, will encrypt the data and will stop backing up the files to user computers. It also has fixed the bug with a free software update.
Kim, the lawyer, took Apple to court earlier this year over iPhone privacy and was awarded 1 million won.
The Korea Communications Commission, South Korea's communications regulator, earlier this month ordered Apple's local operation to pay a 3 million won fine for what it said were violations of the country's location information laws.
Oh Byoung cheol, a professor of information technology law at Seoul's Yonsei University law school, said that the KCC ruling is likely to bolster the plaintiffs' allegations of illegality by Apple and that could have an impact on possible cases in other countries.
But any South Korean court decision on damages is unlikely to have much effect elsewhere given differences in international tort law, he said.
South Korean courts "tend to be stingy with damages for mental suffering," he said.
If the court in the southern city of Changwon rules in favor of the plaintiffs, the total award could come to about 27.6 billion won ($25.7 million). Cupertino, California based Apple the most valuable company in the United States earned $7.31 billion in its fiscal third quarter.
Kim said he expected the first hearing in the new case to take place in October or November.
Jung Ogk taek, an official at the Changwon District Court, said it was not clear how much time would be needed to reach a verdict.
Kim said 26,691 plaintiffs were listed in the civil suit filed Wednesday. Another 921 are minors and lawyers need to obtain the consent of their parents before they can join, Kim said. He expects that to take about two weeks.