Grant Smith got one of the USPS delivery scam text messages. He decided to track the scammers and uncovered a Chinese-language group behind the campaign. He hacked their systems, discovered their mechanisms, and gathered victim data. He handed it to USPS, bank, and FBI investigators – as well published information about their operations online and at Defcon.

He discovered the group sold their scamming kits to set up their own operations for a $200/mo subscription. Similar scams showed up in half dozen other countries.

What’s interesting is he reported how many people fell for it. The triad sent 50,000-100,000 text messages a day. In total, US victims for just this one (albeit very large) operation entered 438,669 credit card numbers. Many people entered multiple cards.

Read more about it here.