A civic group urged LG Uplus to waive cancellation fees after the carrier began replacing all USIM cards over a controversy about International Mobile Subscriber Identity (IMSI) design.

The Seoul YMCA Citizen Relay Room said in a statement on Thursday that expert demonstrations show security threats are becoming real due to LG Uplus' poor IMSI management. It said the company should take user protection measures such as notifying users of the risks and waiving cancellation fees.

According to the group, at a hacking conference held at KAIST on April 8, KAIST professor Yong-dae Kim (김용대) succeeded in tracking the location of a specific LG Uplus handset using an open-source LTE sniffer. It said the IMSI can be inferred using only a phone number and the handset's location can be confirmed.

It also cited a case posted on an online community that showed a process in which a handset's IMSI value was obtained through an IMSI catcher, part of the phone number included in the value was identified and actual calls were connected.

Seoul YMCA stressed that there was clear negligence in IMSI system management because the carrier failed to take the level of protective measures that could reasonably be expected.

Seoul YMCA said the Ministry of Science and ICT has said there is no legal problem, but it has failed to meet user protection responsibilities under Article 3 of the Information and Communications Network Act, which stipulates a duty to provide safe services. It added that, judging by whether there were lapses in IMSI management and whether protective measures were insufficient, there was clear negligence and it could fall under grounds for waiver of cancellation fees under the terms and conditions.

It stressed that LG Uplus should immediately notify all customers by text message of its past IMSI management lapses and the security risks, and that the Ministry of Science and ICT should issue administrative guidance to waive cancellation fees for all LG Uplus customers for a sufficient period.