After TechCrunch reported last week that WhatsApp had a child porn problem, Google and Facebook have removed several third-party apps that led to kiddie porn groups.

WhatsApp confirmed to TechCrunch that they failed to police their own platform. The app is moderated by 300 of the company’s employees and not by Facebook’s team of 20,000.

The ads were supported by Google AdMob, Google Firebase, Facebook Audience Network, and StartApp. The apps were hosting ads for the likes of Amazon, Sprint, and Microsoft.

An app like “Group Links For Whats” by Lisa Sudio seems innocent on the surface – you can navigate through the groups for business advice and sports news. However, there are more sinister links and titles available like “child porn only no adv” and “child porn xvideos.” An ad for Q Link Wireless was displayed before providing a link to a group called “child,” a term commonly associated with child pornography.

Google provided TechCrunch with the following statement:

“Google has a zero tolerance approach to child sexual abuse material and we’ve invested in technology, teams and partnerships with groups like the National Center for Missing and Exploited Children, to tackle this issue for more than two decades. If we identify an app promoting this kind of material that our systems haven’t already blocked, we report it to the relevant authorities and remove it from our platform. These policies apply to apps listed in the Play store as well as apps that use Google’s advertising services.”