Speaking to lawmakers, Verity Harding, the public policy manager for Google, which owns the video website, said approximately 300 hours of video are uploaded every minute by users around the world. That's 12 and a half days of content every minute.
"To pre-screen those videos before they are uploaded would be like screening a phone call before it's made," she said at the meeting, according to the Associated Press.
The meeting comes as the European Union's counter-terrorism chief has called for help from member states to flag terror-related content as soon as it appears.
The first line of defense for YouTube has been relying on users to flag content they deem inappropriate.
"With so much content on the site, it would be impossible to review it all," reads a page explaining YouTube's policy. "That's why we rely on YouTube community members to flag content that they find inappropriate."
While it is not clear how many videos are flagged per day, YouTube said it staffs a team at all hours to review flagged content.
The Associated Press contributed to this report.