A federal judge has rejected claims that AOL and the National Center for Missing and Exploited Children were acting as agents for the government when they searched a Kansas man’s emails for child pornography.

U.S. District Judge Eric Melgren refused Tuesday to suppress as evidence the email and attachments that Walter Ackerman claimed were obtained through an illegal search. The judge also declined to throw out statements the 56-year-old Lebanon man made when agents questioned him.

Ackerman is charged with distribution and possession of child pornography.

AOL uses a process to systematically identify child pornography sent through its services. The company maintains a database of digital fingerprints known as “hash values” associated with child pornography. It sends any matches to the center, which in turn notifies law enforcement.