WASHINGTON, Sept 17 (Reuters) - A U.S. House committee

on Wednesday asked the CEOs of Discord, Steam, Amazon ( AMZN )-owned

Twitch, and Reddit ( RDDT ) to testify at an Oct. 8

hearing on the radicalization of some online forum users.

Representative James Comer, chair of the U.S. House of

Representatives Oversight and Government Reform Committee, said

he was calling the hearing after the assassination of Charlie

Kirk. "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," Comer said.