Hundreds of people in Mumbai, India have been detained in relation to a massive telephone scam where fake callers "from the IRS" targeted Americans. In said calls, scammers tried to convince recipients that they were from the IRS in order to con victims into forking over thousands of dollars payable via prepaid credit cards.

According to The Guardian, 200 Indian police officers raided nine locations across one of India’s largest cities.

"Seventy workers have been formally arrested and around 630 others are being investigated," Paramvir Singh, the police commissioner of Thane, told the British newspaper. "We expect that many more people will be arrested."

Typically, the phone representatives would call Americans and claim to be calling from the IRS, saying that the recipient owed "back taxes," and police are "on their way right now." The callers then would give precise instructions as to how to avoid this situation, which would inevitably involve withdrawing large amounts of cash and going to a store like Target or Walmart to buy a prepaid cash card or using a service like MoneyGram to transfer the money to a particular account.

In May 2016, NPR’s Planet Money spoke with a representative from MoneyGram, who said that he gets "20 calls like this a day"—people calling MoneyGram to check to see if they received a fake call.

"We had a mole go in to the call centres to verify. The best part is that they were actually recording all their calls. We have recovered 851 hard disks on which the calls were recorded, so we’re going through those now," Singh told The Guardian.

Reuters cited local police and reported that "callers were paid between 10,000 rupees ($150) and 70,000 rupees ($1,050) every month."