Since its launch in 2003, Steam has grown to become one of the biggest digital stores for PC games. But bringing so many players together has also had some unexpected consequences in the real world. Now, Virginia Senator Mark Warner is accusing Steam's parent company, Valve, of allowing hate speech, white-supremacist content, and even comments praising terrorists to go unchallenged by the company.

Warner shared his letter with Bloomberg, and addressed his concerns to Valve co-founder Game Newell. Citing a recent report from the Anti-Defamation League's Center for Extremism, Warner writes that Steam has become "an unsafe place for teens and young adults to purchase and play online games" and adds that if the Valve fails to address these issues then it will allow "harmful ideologies to spread and take root among the next generation."

The report mentioned by Warner reportedly identified 1.83 million instances of extremist or hateful content on Steam. Some of examples include Nazi imagery, tributes to individual terrorists, and support for terrorist groups like ISIS. Earlier this year, a Turkish teenager planned a knife attack with someone he met on Steam before carrying out his plans in August while wearing a neo-Nazi symbol.