An individual who inadvertently exposes the contents of his computer over an unsecured wireless network still has a reasonable expectation of privacy against a search of those contents by the police, a federal judge in Oregon ruled last week.
The ruling involves John Henry Ahrndt, a previously convicted sex offender who was sentenced to 120 months in prison for possession of child pornography on his computer.
Ahrndt had argued that some of the evidence that was used against him in court had been gathered illegally. He had filed an appeal asking the U.S. District Court for the District of Oregon in Portland to suppress the evidence on the grounds that his Fourth Amendment rights against unreasonable search had been violated.
Oregon District Court Judge Garr King initially denied Ahrndt's motion to suppress but picked up the case again last year after the U.S. Court of Appeals for the Ninth Circuit reversed King's first ruling.
In a 34-page ruling last week, Kerr granted Ahrndt's renewed motion to suppress the evidence gathered by police from his hard drive and also ordered his subsequent testimony to them to be suppressed as well.
Ahrndt's case goes back to 2007 when one of his neighbors, a woman referred to only as "JH" in court documents, connected to the Internet using her own wireless network. When JH's network temporarily malfunctioned, her computer automatically connected to Ahrndt's unsecured wireless network.
When JH subsequently opened her iTunes software to listen to music she noticed that another user library called "Dads LimeWire Tunes" from Ahrndt's computer, was also available for sharing, court documents said.
When JH clicked on the folder she immediately noticed that it contained a lot of files with names suggesting explicit child pornography. She informed the county sheriff's department which then sent a deputy to take a look at her discovery.
JH showed the deputy a play list of about 25 picture and video files with pornographic titles that she had found on the folder. After consulting with his supervisor, the deputy then asked JH to open one of the files and discovered that it did indeed contain an image depicting child pornography.
Based on that discovery, law enforcement agents obtained a search warrant to search Ahrndt's home. They seized a computer, a wireless router, several hard disks and other storage media from Ahrndt's home. A forensic investigation of the seized equipment turned up about 20 images depicting child porn.
Ahrndt claimed that the search warrant that was used to gather the evidence against him had only been issued based on the deputy's illegal search of his computer files in the first place. He argued that if the deputy had not illegally opened the file on his computer that was available over the unsecured wireless network, there would have been no probable cause to issue the subsequent search warrant.
In analyzing the case, Judge King noted that there was nothing to show that Ahrndt was using or had intended to use iTunes or other file-sharing software to share the files in question, with others. "The invasive action at review here is a remote search of computer data transmitted on an unsecured wireless network," he noted.
King conceded that the deputy did not violate Ahrndt's Fourth Amendment protections by merely looking at the list of files on his computer because the list had had already been pulled up by JH.
However, the deputy's subsequent action in asking JH to open one of the files did violate reasonable expectations of privacy, particularly since Ahrndt had not intended for the contents of his PC to be shared.
King rejected the government's argument that the highly suggestive file names alone were enough reason for probable cause. In his ruling, the judge said it was unlikely the government could have obtained a search warrant based purely on the deputy's recollection of the file names on Ahrndt's collection. In fact, if the deputy had not seen the image, there would have been no probable cause to ask for a search warrant against Ahrndt, he said.
"The mere act of accessing a network does not in itself extinguish privacy expectations, nor does the fact that others may have occasional access to the computer," the judge said, quoting from a previous case involving a similar issue.
"Although Ahrndt's failure to secure his network suggests a lesser subjective expectation of privacy, I could not say he lost all expectation of privacy in the contents of files on his personal computer," King wrote.
Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at @jaivijayan or subscribe to Jaikumar's RSS feed. His e-mail address is firstname.lastname@example.org.
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This story, "Exposure of files on unsecured wireless no excuse to search, judge rules" was originally published by Computerworld.