Google is going on a hiring spree to try to stamp out offensive videos and comments on YouTube.

The company is recruiting thousands of reviewers to reduce the amount of “problematic content” on its video platform. It’s also introducing tougher restrictions on advertising and making greater use of smart technology.

By 2018, Google (GOOGL, Tech30) aims to have more than 10,000 people “working to address content that might violate our policies,” YouTube CEO Susan Wojcicki said in a blog post. She did not say how many people currently monitor YouTube for offensive videos.

“Some bad actors are exploiting our openness to mislead, manipulate, harass or even harm,” Wojcicki said, adding that YouTube’s trust and safety teams have reviewed nearly 2 million videos for violent extremist content over the past six months.

“We are also taking aggressive action on comments, launching new comment moderation tools and in some cases shutting down comments altogether,” she said.