On Tuesday, a federal judge in Tacoma, Washington, sentenced David Tippens to six months in prison for one remaining count of possession of child pornography that he obtained via the now-defunct, notorious Tor-hidden child porn website, Playpen.

In a sentencing memorandum filed last month, prosecutors asked the judge to impose a much longer sentence.

"The Government asked for 48 months in prison but the Court was impressed with Mr. Tippens' long and distinguished service in the Army, including combat duty in Iraq; his cooperation with the police at the time of his arrest and perfect compliance with pre-trial supervision; and the fact that he had a pornography addiction related to PTSD that would be addressed through continuing counseling," Tippens’ federal public defender, Colin Fieman, e-mailed Ars.

Earlier this year, Tippens, a sergeant in the United States Army, was found guilty of a single count after two other counts were dropped when prosecutors acknowledged that material the defense wished to present was classified and that it therefore should be excluded. Because of that declaration, and the inability to present classified material that may possibly be helpful to the defense, the defense asked the judge to dismiss Counts 1 (receipt of child pornography) and 3 (transportation of child pornography). The remaining count of possession of child pornography carries no minimum sentence.

Like all of the more than 200 Playpen prosecutions unfolding nationwide as part of the FBI’s "Operation Pacifier," Tippens was discovered through the government's seizure and temporary operation of Playpen. During that 13-day period in 2015, federal authorities deployed an exploit to logged-in users of the site, which had the effect of forcing users’ computers to expose their true IP address. With such information, associating a suspect with an IP address became trivial for the investigators. The Department of Justice has called this exploit a "network investigative technique," (NIT) while many security experts have dubbed it as "malware."

These prosecutions, which are still unfolding nationwide, have raised significant questions as to what the limits of government surveillance should be—and how much judicial and legislative oversight exists for authorized government hacking. For now, most defendants have accepted plea deals. However, two months ago, three advocacy organizations put out a lengthy legal guide for criminal defense attorneys who are struggling to deal with understanding this cutting-edge area of the law.

“Imprisonment and lengthy supervision”

The sentencing memorandum , which describes in graphic detail Tippens’ behavior and the lengths to which he went in order to conceal his habit from his own children—including soundproofing his bedroom—made a strong case for a lengthy incarceration.

"For years, Tippens has concealed his dangerous sexual desires," Assistant United States Attorney Matthew P. Hampton wrote. "And still, there is no indication at this point that he has truly accepted responsibility for his crime or began the hard work necessary to confront and control his impulses. Imprisonment and lengthy supervision are not only appropriate but essential."

Tippens will remain out of custody on bond while his appeal is proceeding.

"I will now be focusing on his appeal, and look forward to the 9th Circuit's review of the FBI's ill-conceived Operation Pacifier and all of the legal issues that surround it," Fieman added.

When Ars asked the United States Attorney’s office in Tacoma whether it would be appealing the sentence or had any further comment, we only received a brief reply.

"We don't have anything further to say beyond what was in our sentencing memo," Emily Langlie, a spokeswoman, e-mailed.