When a computer on any of the networks responded with a query-hit message indicating it had a file matching the query term, the software recorded the IP address, hash values of the files, the actual file names, date and time of response and other details of the computer. The hit message identified files on a particular system that matched the query terms and were available for download by other users on the same P2P network.
The software allowed investigators to automate the process of sending out queries and receiving search results. It even allowed them to filter results in such a manner as to ensure that the only hits returned were from IP addresses within each investigator's jurisdiction.
The searches showed that computers belonging to the three defendants contained files with digital signatures that exactly matched files that were known to contain images depicting the exploitation of children. Investigators used this information to obtain the probable cause search warrants that eventually led to the arrest and indictments of the three individuals.
In rejecting the motion to suppress the evidence, Reiss noted that the automated search tool had not opened or downloaded any of the files on the defendants' computers. All the tool did was identify files that the defendants themselves had made publicly available for download on the Internet via a P2P network.
The fact that the tool used to conduct the search was proprietary or automated does not make a difference, the judge ruled. The same results would have ensued if investigators had conducted the searches manually.
"This software is designed to replace the searches that were previously done manually by law enforcement and the public. The software reports information that is discoverable by the general public using publicly available P2P software," the judge said. There was nothing in the evidence or the arguments presented by the defense to show that the tool had somehow accessed private files that were not meant for sharing, she said.
Pointing to previous rulings in similar cases, the judge noted that even if the defendants had meant to keep the files private, the fact that they were publicly accessible negated any expectations of privacy. "Defendants conveyed certain information to the public when they used peer-topeer file sharing software and made certain files available for sharing," she wrote.
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