Alphabet Inc's Google unit told a US House panel it spends hundreds of millions of dollars annually on content review and said it manually reviewed more than one million suspected "terrorist videos" on YouTube in the first three months of 2019.
Google disclosed in an April 24 letter made public on Thursday that the manual review found 90,000 videos violated its terrorism policy.
In March, following the live-streaming on social media of a mass shooting in New Zealand, the chair of the US House Committee on Homeland Security urged the top executives of Google, Facebook Inc, Twitter Inc and Microsoft Corp do a better job of removing violent political content.
After a briefing in March, Representative Max Rose, who chairs a subcommittee on intelligence and counter-terrorism, asked the four companies in an April 10 letter to disclose their budgets for counter-terrorism programmes and number of people working solely on counter-terrorism programmes.
Rose said in a statement Facebook has not responded and the other firms did not fully or directly answer his questions.
Twitter said in an April 24 to Rose that "putting a dollar amount on our broader efforts is a complex request."
Twitter said a "substantial portion" of its 4,100-person global workforce are involved in reviewing content.
Alphabet's first quarter costs rose about the same as revenue, up 16.5 percent from last year to $29.7 billion, reports Reuters.
