Phishing emails and social engineering scams were all it took for mobile phone store owner Argishti Khudaverdyan to breach the mobile provisioning systems of T-Mobile, AT&T, and Sprint to “unlock” phones from their network constraints — earning him more than $25 million in the process.

Now Khudaverdyan has been convicted and sentenced to 10 years in federal prison for wire fraud, money laundering, and identity theft, among other counts.

In all, Khudaverdyan stole the credentials of more than 50 T-Mobile employees across the US, allowing him to unblock hundreds of thousands of phones, according to the Department of Justice.

“From August 2014 to June 2019, Khudaverdyan fraudulently unlocked and unblocked cellphones on T-Mobile’s network, as well as the networks of Sprint, AT&T, and other carriers,” the DOJ explained. “Removing the unlock allowed the phones to be sold on the black market and enabled T-Mobile customers to stop using T-Mobile’s services and thereby deprive T-Mobile of revenue generated from customers’ service contracts and equipment installment plans.”