Korean civic groups together filed a complaint Wednesday, challenging the constitutionality of the local authorities' collection of user information from mobile carriers without a warrant.

The Lawyers for a Democratic Society, or Minbyun, said 500 people, including professors, filed the complaint with the Constitutional Court.

Under the current law, local investigative authorities, such as police, prosecution and intelligence agency, can gather personal information of mobile carrier users without a warrant. The information include users' registration number, address and phone number.

The law has been in place to make it possible for local law enforcement and the intelligence service to counter crime, terrorism and espionage.

"Among the applicants, there is a person whose personal information was provided to the authorities seven times," the progressive lawyers' association claimed. "It means government bodies indiscriminately gathered the information according to their convenience."

The law also does not mandate that the mobile carriers inform users when their information is given to the authorities, according to the association.

In 2014, investigative authorities received some 13 million pieces of communication data from portals and mobile carriers, sharply increasing from 9.57 million a year earlier and 7.87 million in 2012, government data showed. (Yonhap)