With fresh indictments of Chinese hackers on the record, the U.S. government may prevent Chinese nationals from attending U.S. hacker events this summer.

Washington is considering using visa restrictions to prevent Chinese hackers from attending DefCon and Black Hat, two popular hacker conferences scheduled to take place this August in Las Vegas, an unnamed “senior administration official” told Reuters Saturday. The move would be part of a broader effort to curb Chinese espionage, said the official.

On Monday, the U.S. indicted five members of the Chinese military for allegedly hacking into six American corporations to steal trade secrets, including access to executives’ emails and the design of a nuclear power plant. China has repudiated the charges, calling them “made up.”

Jeff Moss, who founded both DefCon and Black Hat, believes preventing Chinese hackers from attending the events is a bad idea.

BlackHat and DefCon presentations include discussions of software vulnerabilities, cryptography, and more.