Google is not alone in scanning for illegal content.
A Pennsylvania man has been charged with possessing and distributing images of child sexual abuse, following a tip-off from Microsoft.
The suspect, named as 20-year-old Tyler James Hoffman, is alleged to have uploaded the offending photos to the company's OneDrive cloud storage service via his Microsoft Live email account on his smartphone.
According to the police report, which was filed with the Monroe County Court last week, Microsoft detected in April that an image of child abuse had been uploaded to OneDrive. The company then contacted the National Center for Missing and Exploited Children (NCMEC), which informed the police.
It was discovered the email address was linked to Hoffman's Facebook address which, combined with an IP address trace, led to his arrest.
The revelation follows news earlier this week that a tip-off from Google regarding child abuse images being stored in Gmail had also led to an arrest.
As with Microsoft, Google notified the NCMEC that it had detected the images, which passed the tip on to the Houston Police Department, leading to the arrest of alleged offender John Henry Skillern.
According to The Smoking Gun, when questioned by police Hoffman allegedly admitted trading images of child sexual abuse and uploading them to Microsoft's cloud.
In a statement to the BBC, Mark Lamb from Microsoft's Digital Crimes Unit, said: "Child pornography violates the law as well as our terms of service, which makes clear that we use automated technologies to detect abusive behaviour that may harm our customers or others."
"In 2009, we helped develop PhotoDNA, a technology to disrupt the spread of exploitative images of children, which we report to the National Center for Missing and Exploited Children," he added.
PhotoDNA is a hash function technology that automatically detects when one image is like another.
The NCMEC, to whom Microsoft donated PhotoDNA, uses the technology to create a digital fingerprint of the "worst of the worst" images of child sexual abuse in its database.
The tool is then used by Microsoft's Bing and OneDrive products, as well as Twitter, Facebook, and Gmail to compare images on their services with ones listed on the NCMEC'S database.
Hoffman will appear before magistrates for an initial hearing on 14 August.