John Henry Skillern, 41, from Houston was arrested by police for possession of child pornography. The police were tipped off by Google after finding the illegal content in the defendant’s mail.

The police say they discovered more evidence of child pornography on Skillern’s devices.

“Google has seen in Skillern’s email three allegedly pornographic pictures of children and had informed the National Center for Missing and Exploited Children,” the Police told KHOU-TV.

Google has never kept secret of the fact that it reads email content. In its April Term of Service, Google clarified that its “automated systems examine your content, including emails.” The company further clarified that the  analysis happens as the content is sent, obtained and stored. The changes came soon after the company was sued in California over its email scanning being employed to deliver ads to college students.

According to a Google spokeswoman, the company does not comment on personal accounts. However, it has been clear about making use of technology, which other sites use too, to try to identify child pornography across the web.

The company confirmed that it does not wish to disclose too much of its operations since it does not want criminals to be aware of how they can be caught. For Google, trying to eradicate child pornography takes priority over what others might look at private communication. It is an argument with underlying dangers.