After news came to light last month that Line Corp. had allowed a Chinese software company to access users’ personal information despite Beijing’s tighter data control regulations, the firm was roundly criticized over its handling of personal information and has taken to revising its data-handling policy.

The operator of the Line messaging app said it had cut access from China and also plans to move sensitive data stored in South Korea to Japan.

But the question remains over what went wrong with Line’s data management.