The telecom ministry on Friday again urged Internet service provider Softbank BB Corp. to take better care to prevent customer information from being stolen or leaked, ministry officials said.
The Public Management, Home Affairs, Posts and Telecommunications Ministry summoned Softbank Corp. President Masayoshi Son, also the head of Softbank BB, and gave him an "administrative guidance" paper to this effect, the officials said.
Softbank BB was given a similar warning in April after information on 4.5 million subscribers was stolen by an extortion group in January.
The ministry officials said the company could not detect the leak of phone records when it conducted an in-house investigation in February after discovering the January theft. The ministry had been considering giving the company a business improvement order.