Nearly 5 million Google users are named in a recent hack that appears to have originated in Russia. Reuters

Online Search giant Google Inc (NASDAQ:GOOGL), which electronically monitors content accessed by its users for evidence of child sexual abuse, defended the practice when Texas police arrested a child pornography suspect after receiving a tip-off from the company, Agence France-Presse, or AFP, reported.

John Henry Skillern, a 41-year-old restaurant worker, was arrested Thursday in Houston after Google passed on critical information to the National Center for Missing and Exploited Children, or NCMEC, located outside Washington, which also operates the CyberTipline, through which Internet service providers can relay information about suspected online child sexual abuse to the police.

Skillern was reportedly convicted 20 years ago of sexually assaulting an eight-year-old boy, and investigators who raided his home last week found child pornography on his phone and tablet device, along with phone videos taken of children visiting the Denny’s restaurant where he worked as a cook.

Detective David Nettles, of the Houston Metro Internet Crimes Against Children Taskforce, told KHOU, a Houston television station: “He was trying to get around getting caught, he was trying to keep it inside his email,” adding: “I can't see that information, I can't see that photo but Google can.”

Most of the world’s biggest Internet service companies, like Google, track users' online behavior to help them pitch relevant products to them in the form of online advertisements. After the arrest in Texas, however, concerns have been raised about the kind of user conduct and information Google might be handing over to law enforcement.

Google’s “program policies” for its Gmail service, an email service with over 400 million users across the globe, includes “a zero-tolerance policy against child sexual abuse imagery."

"If we become aware of such content, we will report it to the appropriate authorities and may take disciplinary action, including termination, against the Google accounts of those involved," the policy states.

A Google spokesperson on Monday said, in an email to AFP, that, "Sadly, all Internet companies have to deal with child sexual abuse,” explaining, “It’s why Google actively removes illegal imagery from our services, including search and Gmail and immediately reports abuse to the NCMEC."

"Each child sexual abuse image is given a unique digital fingerprint which enables our systems to identify those pictures, including in Gmail," adding: "It is important to remember that we only use this technology to identify child sexual abuse imagery not other email content that could be associated with criminal activity (for example using email to plot a burglary).”

NCMEC also sent a separate email to AFP in which it said that federal law requires Internet service providers to report suspected child porn to the CyberTipline, and added that, "NCMEC makes all CyberTipline reports available to appropriate law-enforcement agencies for review and possible investigation."

Last year, David Drummond, Google’s chief legal officer, acknowledged that Google possessed technology to “trawl” for images of child sex abuse and stated that, "We can then quickly remove them and report their existence to the authorities."