Sam Bankman-Fried has been using a VPN while under house arrest, and prosecutors aren't happy

• Federal prosecutors on Monday raised concerns about Sam Bankman-Fried's recent use of a VPN.
• VPNs allow individuals to covertly access crypto exchanges and the dark web, prosecutors said.

Sam Bankman-Fried has on two occasions used a virtual private network (VPN) to mask his web connection while under house arrest, federal prosecutors have said.

In a letter to US District Judge Lewis Kaplan, who's overseeing Bankman-Fried's criminal case, Assistant US attorney Danielle R. Sassoon wrote the government "informed defense counsel and raised concerns" about the defendant's use of a VPN on January 29 and February 12.

A VPN is a form of software that masks a user's web-browsing activity and location. While Bankman-Fried is under home confinement ahead of his criminal trial, prosecutors want to be able to access all his messages and browsing activity to build their fraud case against him.

Sassoon wrote in her letter, dated Monday, that the government didn't dispute that "many individuals use a VPN for benign purposes." However, she said Bankman-Fried's use of a VPN "raises several potential concerns."

Among these concerns, Williams wrote, were that some individuals "use VPNs to disguise the fact that they are accessing international cryptocurrency exchanges," that VPNs allow "data transfers without detection through a secure, encrypted connection," and that they offer "a more secure and covert method of accessing the dark web."

In a letter to Kaplan on Tuesday, Bankman-Fried's lawyers wrote that on the dates referenced by Sassoon, Bankman-Fried "used the VPN to access an NFL Game Pass international subscription that he had previously purchased when he resided in the Bahamas, so that he could watch NFL playoff games."

The lawyers said Bankman-Fried watched the AFC and NFC Championship games on January 29, and the Super Bowl on February 12.

They added: "This use of a VPN does not implicate any of the concerns raised by the government in its letter."

On Thursday, Kaplan extended his ruling that Bankman-Fried cannot use messaging apps with auto-delete functionality. "I've read all the spy novels," the judge said. "You don't think this defendant is bright enough to encrypt something in writing?"

Prosecutors and Bankman-Fried's defense attorneys are currently attempting to negotiate new parameters that would determine how Bankman-Fried will be able to use messaging apps while he's under home confinement in his parents' home in California, ahead of a criminal trial for fraud charges in New York related to how he ran his cryptocurrency trading platform FTX.

Bankman-Fried was previously banned from contacting FTX employees after a request from the Department of Justice, and Kaplan expressed concern at last week's meeting that he could try to influence other witnesses.

Bankman-Fried's FTX was one of four crypto companies to air advertisements during last year's Super Bowl. FTX's ad featured Larry David, whose character is told how the crypto exchange is "safe and easy." He responds: "I don't think so. And I'm never wrong about this stuff. Never."

This year there were no adverts for crypto companies screened during the Super Bowl. Some crypto companies had completed ad deals for Sunday's event but pulled out after FTX's bankruptcy, Insider previously reported.

A spokesperson for Bankman-Fried declined to comment.