"Joshua Gonzalez, a computer technician in Texas, was arrested this year with over 400 images of child sexual abuse on his computer, including some of E. and her sister.

Mr. Gonzalez told the authorities that he had used Microsoft’s search engine, Bing, to find some of the illegal photos and videos, according to court documents.

Microsoft had long been at the forefront of combating abuse imagery, even creating the PhotoDNA detection tool a decade ago. But many criminals have turned to Bing as a reliable tool of their own.

A report in January commissioned by TechCrunch found explicit images of children on Bing using search terms like “porn kids.” In response to the report, Microsoft said it would ban results using that term and similar ones.

The Times created a computer program that scoured Bing and other search engines. The automated script repeatedly found images — dozens in all — that Microsoft’s own PhotoDNA service flagged as known illicit content. Bing even recommended other search terms when a known child abuse website was entered into the search box."