Meanwhile, the larger lessons of the backdating furor were drawn in an epic piece in May in the American Bar Association's ABA Journal. By freelance reporter Anna Stolley Persky, the piece connected the dots between (among other things) the backdating witch-hunt, the tainted prosecution of Sen. Ted Stevens, and the government's use of the vague "honest services" statute to criminalize various kinds of behavior post hoc (a practice the Supreme Court finally curbed earlier this year).

One critique can be found in the title of a book by Boston defense attorney Harvey Silverglate: "Three Felonies a Day: How the Feds Target the Innocent." Mr. Silverglate believes that only a mobilization of "civil society" can stop what he calls rampant abuse of prosecutorial discretion.

One of the many sobering subtexts to Three Felonies a Day is that the U.S. has the highest rate of incarceration in the civilized world. The Economist shines a bright light on this phenomenon in its current issue, and highlights the role that vague statutes play in this prosecution mill.

The system has three big flaws, say criminologists. First, it puts too many people away for too long. Second, it criminalises acts that need not be criminalised. Third, it is unpredictable. Many laws, especially federal ones, are so vaguely written that people cannot easily tell whether they have broken them.

Innocent defendants may plead guilty in return for a shorter sentence to avoid the risk of a much longer one. A prosecutor can credibly threaten a middle-aged man that he will die in a cell unless he gives evidence against his boss. This is unfair, complains Harvey Silverglate, the author of “Three Felonies a Day: How the Feds Target the Innocent”. If a defence lawyer offers a witness money to testify that his client is innocent, that is bribery. But a prosecutor can legally offer something of far greater value—his freedom—to a witness who says the opposite. The potential for wrongful convictions is obvious.

WBUR-90.9-FM, one of Boston’s NPR-affiliated stations, this week ran a three-part report, by reporter David Boeri, on a remarkable case that has arisen in the federal court in Boston, in which evidence of alleged serious misconduct on the part of a federal prosecutor has been uncovered. Boeri interviewed me in parts 2 and 3 of his report, because – I assume – of my long-standing concern with Department of Justice tactics that pose a serious risk of convicting the innocent.