FILE PHOTO: Candles and flowers are placed near an image of conservative activist Charlie Kirk with his family, during a vigil for him in Statuary Hall of the U.S. Capitol in Washington, D.C., U.S., September 15, 2025. REUTERS/Ken Cedeno/File Photo

By David Shepardson

WASHINGTON (Reuters) - A U.S. House committee on Wednesday asked the CEOs of Discord, Steam, Amazon-owned Twitch and Reddit to testify at an Oct. 8 hearing following the assassination of Charlie Kirk, citing the "radicalization of online forum users."

Kirk, 31, co-founder of the conservative student movement Turning Point USA and a key ally of President Donald Trump, was speaking at an event attended by about 3,000 people when he was gunned down last week.

"In the wake of this tragedy, and amid other acts of politically motivated violence, Congress has a duty to oversee the online platforms that radicals have used to advance political violence," Republican Representative James Comer, chair of the U.S. House of Representatives Oversight and Government Reform Committee, said in a letter to the four companies.

The companies did not immediately respond to requests for comment.

"The hearing will examine radicalization of online forum users, including incidents of open incitement to commit violent politically motivated acts," the letter to the companies said.

Roughly two out of three Americans believe that harsh rhetoric common in politics is encouraging violence, according to a Reuters/Ipsos poll conducted in the days following Kirk's murder.

(Reporting by David Shepardson; Editing by Leslie Adler)