YouTube is working at a feverish pace to rid its platform of a problem that threatens the brand’s reputation.

The Google-owned video-sharing site tells Variety that over the past week, it has removed more than 150,000 videos featuring children that had been targeted in the comments section by pedophiles. YouTube has additionally disabled comments for over 625,000 videos and terminated several hundred accounts that had been used to publish predatory comments on videos starring minors.

It doesn’t stop there, however, as YouTube has also removed advertisements from nearly two million videos and over 50,000 channels that were “masquerading as family-friendly.”

The matter has become quite serious for Google and YouTube. Bad PR look aside, the issues have prompted several big-name advertisers including HP, Mars, Cadbury, Deutsche Bank and Adidas to freeze ad spending on the platform.

A representative for HP told Variety that they have strict brand safety protocols in place across all online advertising, including YouTube. HP suspended all advertising worldwide on YouTube after learning that one of its ads was placed “in a terrible and inappropriate context.” That instance, the spokesperson said, appears to be the result of a content misclassification by Google.

Tougher enforcement on YouTube’s part should help to ensure that stuff like this isn’t a problem moving forward. Given YouTube’s scale, however, scrubbing the site and keeping it squeaky clean could prove to be a challenge, one that potentially opens the door for competitors like Jellies.