* This is a district court Judge’s ruling on a motion, which has not yet withstood appellate scrutiny. However the issues presented are important to capture emerging trends in the field.
Defendant was indicted January 10, 2013 with on one count of possession of child pornography of a child under 12; two counts of receiving child pornography involving prepubescent minors; and two counts of distributing child pornography involving a prepubescent minor. He filed a motion to suppress contesting the validity of the search warrant.
This is a standard P2P investigation, on the eDonkey network, using eMule file sharing software. The crux of defendant’s argument is that the Child Protection System (CPS) software used by law enforcement constituted a search, for purposes of triggering the 4th Amendment.
Background on CPS: “To root out purveyors of child pornography on these P2P networks, law enforcement agencies have developed specialized software to troll public networks, identify files containing child pornography, locate the users sharing these files, and catalog all of this public information. CPS is one example…It analyzes the hash values assigned to files available for download on the eDoneky network and compares them to files stored in government databases that contain known images of child pornography. The eMule software generates a hash value for each image or video based on its content, using the MD4 algorithm. This hash value is viewable to all eMule users. Because each hash value is essentially one of a kind, it assures law enforcement officials there is a high likelihood that child pornography is contained on the computer using the identified…IP address. CPS essentially automates the searches any normal human user can run on eMule and then stores the relevant information in a special law enforcement database. The program cannot search for private files on a computer if that user has not elected to make his files public.
Attack on Search Warrant: Defendant claimed the warrant was a result of an illegal search, a warrantless search, and the good faith exception does not apply.
Defendant’s argument is faulty because CPS does not actually search the contents of a person’s computer. It functions in the very same way the eMule software does, the only difference is CPS captures IP addresses and catalogues information for later use by law enforcement. A normal user begins his search for a file by typing in search terms in the query field. A list of files with file names are then returned. “Once a particular file is selected, eMule finds other users on the network sharing that same file to speed up the download process…this is accomplished by eMule comparing the hash values…”
The Judge ruled that defendant does not have an expectation of privacy when he eposes those files to unknown users on the eDonkey P2P network. “Additionally, the Court finds a user of file-sharing software has no reasonable expectation of privacy in his publicly shared files because it is not an expectation of privacy that society is willing to recognize.” United States v. Samples, No. 3-08-CR-12, 2011 WL 4907315, at *5 (N.D. Tex. Sept. 15, 2011).