Flawed understanding of the database!
The article authors have Flawed understanding of hashing. Each IMAGE of the database posses its own hash value therefor if the database holds 4.4 million IMAGES it should only hold 4.4 million hashes. So what are the other 25.6 million hashes of if they are not tied to an image?? If law enforcement has the ability to find child porn they also posses the ability to delete it with those same hash values without the Gothic Melodrama of arrest.