Google isn’t alone in its email scanning for child porn. Software giant Microsoft recently tipped off police to a man in Pennsylvania who has now been arrested and charged with receiving and sharing child porn through his OneDrive account. The arrest comes just days after news of Google’s own tip off to police, resulting in a 41-year-old restaurant worker being placed in custody for possessing child pornography.

Microsoft's PhotoDNA tech helps identify child abuse images

Microsoft’s police tip offs should come as no surprise though. Court records last year showed that the company initiated a similar tip off to alert authorities about child pornography on a OneDrive account. Microsoft scans emails and cloud storage using its PhotoDNA technology that calculates a mathematical hash for an image of child sexual abuse that allows it to recognize photos automatically even if they have been altered. Google, Twitter, and Facebook all use Microsoft’s PhotoDNA tech, helping to build up a database of illegal photos.

Unlike Google, Microsoft’s email scanning doesn’t result in ad targeting as a result of keywords in messages. Google has been quick to point out that its scanning for illegal activities is strictly limited to child pornography, so if you’re planning an elaborate heist over Gmail then Google won’t report you to authorities. Privacy advocates still have concerns over emailing scanning, particularly when it relates to ads and the sharing of private information. Both cases highlight that online services are far from private, even if a child porn scanning system is seen as a necessary and welcome solution that produces results.