A Houston man named John Henry Skillern was arrested after Google alerted authorities about illegal photos of children in his Gmail account. The 41-year-old, who works at a Denny's restaurant in Pasadena, is a registered sex offender, convicted of sexually assaulting a child in 1994.

The search giant informed the National Center for Missing and Exploited Children after detecting three allegedly pornographic images of children in Skillern's email. The Center then alerted the police, which in turn used the information to get a warrant. According to the police, the raid yielded more than what Google knew was there.

"He was trying to get around getting caught, he was trying to keep it inside his email. I can't see that information, I can't see that photo, but Google can", said Detective David Nettles of the Houston Metro Internet Crimes Against Children Taskforce. The man is currently being held on a $200,000 bond.

Google has been fighting against online child sexual abuse since 2006. The search giant has already made it harder to find child porn content, images and videos, via its search engine, and now its clear that the company is actively monitoring emails, too.

Back in April, the company updated its terms of service to clearly reflect that its automated systems analyze user content (including emails) to provide features such as customized search results, tailored advertising, and spam and malware detection.

While Google's email scan has helped police arrest a culprit in this case, the fact that the company scans email content, and can share it with authorities, will undoubtedly raise privacy concerns.