Hacker-activist group Anonymous India has accused Reliance Jio of sharing user call data with foreign advertising networks, NDTV reported on Monday. Call data was being shared with companies in the United States and Singapore, Anonymous alleged in a blog post. This is the second time that the group is making such an accusation, after it made one in 2015.

The group said that data from Jio’s My Jio and Jio Dialer apps was being sent to an ad network called Mad-Me. It further said that the mobile company was using a third party software development kit to transfer the data without verifying the nature of the data being collected or where it was being sent. “This violates user privacy,” Anonymous said.

It also posted a series of steps for users to re-create the data-sharing process. However, the group acknowledged that the company’s chat app Jio Chat was more secure than it was last year, according to The Hindu Business Line.

Denying the accusations, Reliance Jio said it took the security and privacy of its customers very seriously, and that it only used its collected data to “deliver [a] better quality of service” to them. The company further said it did not share data with any other party in keeping with its “highest standards of governance”.

The mobile network was launched by Reliance Industries Limited chairperson Mukesh Ambani on September 1. Ambani said data services will be offered at as low as Rs 50 per GB. Voice calls will be offered free of cost to all Jio customers, and roaming will be free across India. Customers can get a Jio SIM within 15 minutes if they present an Aadhaar card, Ambani said.