This isn’t about DFU mode, exploiting bugs, or clever SIM hacks. These people broke into the telcom systems to actually unlock these devices for good.
«In total, Khudaverdyan and others compromised and stole more than 50 different T-Mobile employees’ credentials from employees across the United States, and they unlocked and unblocked hundreds of thousands of cellphones during the years of the scheme. Khudaverdyan obtained more than $25 million for these criminal activities.»