Share this article

T-Mobile Sued Over SIM Attack That Resulted in Loss of $450K in Bitcoin

The plaintiff lost 15 bitcoin after an interaction with a T-Mobile customer who had been victim of a SIM-swapping attack.

Updated Sep 14, 2021, 12:11 p.m. Published Feb 12, 2021, 11:15 a.m.
sim, sim swap

T-Mobile is being sued by a customer as a result of a SIM attack that resulted in over losses of over $450,000 in cryptocurrency.

STORY CONTINUES BELOW
Don't miss another story.Subscribe to the Crypto Daybook Americas Newsletter today. See all newsletters

  • The plaintiff, Calvin Cheng, lost 15 bitcoin after an interaction with Brandon Buchanan, T-Mobile customer and co-founder of investment fund Iterative Capital, who had been victim of a SIM-swapping attack.
  • California resident Cheng received a message via Telegram that he believed was from Buchanan offering him an above market value rate for 15 BTC in May 2020.
  • The plaintiff's attorneys claim that T-Mobile's "systemic and repeated failures" to protect customers' sensitive information despite increasingly frequent SIM attacks is to blame.
  • The complaint, filed Monday in the Southern District of New York, alleges T-Mobile violated federal laws and was negligent in its hiring and training of customer service personnel.
  • T-Mobile has claimed that it maintains the highest standard of authentication procedures to protect its customers in the face of account takeover fraud.
  • In a similar case, crypto investor Michael Terpin is suing AT&T for $23.8 million, the dollar value of cryptocurrencies that he had stolen in 2018.

See also: Alabama Man Charged Over SIM Swap Hacks That Stole $150K in Crypto

More For You

Protocol Research: GoPlus Security

GP Basic Image

What to know:

  • As of October 2025, GoPlus has generated $4.7M in total revenue across its product lines. The GoPlus App is the primary revenue driver, contributing $2.5M (approx. 53%), followed by the SafeToken Protocol at $1.7M.
  • GoPlus Intelligence's Token Security API averaged 717 million monthly calls year-to-date in 2025 , with a peak of nearly 1 billion calls in February 2025. Total blockchain-level requests, including transaction simulations, averaged an additional 350 million per month.
  • Since its January 2025 launch , the $GPS token has registered over $5B in total spot volume and $10B in derivatives volume in 2025. Monthly spot volume peaked in March 2025 at over $1.1B , while derivatives volume peaked the same month at over $4B.

More For You

Bitcoin’s Deep Correction Sets Stage for December Rebound, Says K33 Research

(Unsplash)

K33 Research says market fear is outweighing fundamentals as bitcoin nears key levels. December could offer an entry point for bold investors.

What to know:

  • K33 Research says bitcoin’s steep correction shows signs of bottoming, with December potentially marking a turning point.
  • The firm has argued that the market is overreacting to long-term risks while ignoring near-term signals of strength, like low leverage and solid support levels.
  • With likely policy shifts ahead and cautious positioning in futures, K33 sees more upside potential than risk of another major collapse.