Reason contributor Harvey Silverglate was in the Boston Globe over the weekend with a cautionary tale out of the Boston bombing investigation about how the FBI decides when you are lying to it--and the real potential criminal consequences of even talking to them at all.

THOSE CONCERNED with the survival of American civil liberties during the post-9/11 (and now post-Boston Marathon) “age of terror” most commonly fear the federal government’s technical ability to record and store virtually all telephonic and electronic communications. But a more immediate threat to liberty lies in what one particular agency, the Federal Bureau of Investigation, refuses to record, as Robel Phillipos is now learning the hard way.

Phillipos is a 19-year-old Cambridge resident, former UMass Dartmouth student, and friend of alleged Marathon bomber Dzhokhar Tsarnaev. He faces charges of making materially false statements during a series of interviews with FBI agents. If convicted, he could get up to eight years in federal prison and a $250,000 fine.

Phillipos underwent four FBI interviews. He is not alleged to have had any advance knowledge of, much less role in, the bombing itself....

FBI agents always interview in pairs. One agent asks the questions, while the other writes up what is called a “form 302 report” based on his notes. The 302 report, which the interviewee does not normally see, becomes the official record of the exchange; any interviewee who contests its accuracy risks prosecution for lying to a federal official, a felony. And here is the key problem that throws the accuracy of all such statements and reports into doubt: FBI agents almost never electronically record their interrogations; to do so would be against written policy.

Silverglate points out that the FBI explicitly defends this policy with a statement that he sums up as: "Translated from bureaucratese: When viewed in the light of day, recorded witness statements could appear to a reasonable jury of laypersons to have been coercively or misleadingly obtained." And the FBI itself is the sole holder of any evidence that could acquit or convict the person accused of lying to them. Not quite cricket, and a charge that in general should be looked at with very doubtful eyes by judges.