The US Department of Justice has filed lawsuits ( PDF and PDF) against two small telecommunications providers that have allegedly connected hundreds of millions of fraudulent robocalls from Indian call centers to US residents. The Feds want a New York federal judge to cut off the companies' access to the US telephone network. The government says a judge has already issued a restraining order against one of the defendants.

ARS TECHNICA This story originally appeared on Ars Technica, a trusted source for technology news, tech policy analysis, reviews, and more. Ars is owned by WIRED's parent company, Condé Nast.

Fraudulent robocalls are a serious problem in the United States—and the Justice Department says two US companies contributed significantly to the problem. Over a 23-day period in May and June of last year, for example, defendant TollFreeDeals connected 720 million calls to US numbers. According to the Justice Department, 425 million of the calls lasted for one second or less—suggesting that many were unwanted.

The Feds say that during those two months, TollFreeDeals connected 182 million calls from a single India-based call center. Of these calls, more than 90 percent appeared to come from one of 1,000 source numbers. And of those numbers, more than 80 percent have been associated with fraudulent robocalls.

Foreigners seeking to scam American consumers need access to the US telephone network. The two US companies sued by the Justice Department served as VOIP-based gateways between foreign call centers and the US telephone network. They were tiny operations; according to the government, each company did business from the home of its owner.

The companies' overseas clients engaged in a number of scams that might sound familiar to anyone who owns a phone in the US. In one popular scam, fraudsters pretend to work for the Social Security Administration and inform victims that their Social Security number has been "suspended." Other scam callers impersonated the IRS, Microsoft, or other large American organizations. In all cases, the suggested remedy was the same: send the scammers money to help clear up the problem.

In one case, the Feds say, a man was told that officials were about to seize the contents of his bank account. The caller claimed to be from the US Marshals Service and told the man to wire his savings—$9,800—to the scammer for safekeeping. The man did so. By the time he realized he'd been scammed, his bank said the money was gone.

The Feds don't allege that US telecom providers directly executed these frauds. However, they say, the providers turned a blind eye to rampant criminal activity occurring on their networks. Over a period of years, the companies received numerous warnings from other telecom providers that their services were being used for fraud. Federal officials say they did as little as they could to stop the activity while the scammers continued to operate.

The lawsuit is just the latest front in the federal government's ongoing war against robocalls and other fraudulent use of the telephone system. With some prodding by the FCC, telephone providers have been implementing a system called SHAKEN/STIR to authenticate caller information. Congress also recently passed legislation mandating the use of the SHAKEN/STIR technology—albeit with a rather lenient deadline of 18 months.

"The Department of Justice will pursue to the fullest extent of the law individuals in the United States who knowingly facilitate imposter fraud calls, using both criminal and civil tools where appropriate," Assistant Attorney General Jody Hunt said in a statement.

This story originally appeared on Ars Technica.

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