The revelation that the U.S. Department of Justice recently subpoenaed a large number of Associated Press telephone records has led to renewed calls for a federal reporter’s shield law.

A shield law generally prohibits compelling reporters to identify their confidential sources and protects reporters’ notes, telephone records and other work product from disclosure. Congress came close to passing such a law a few years ago in the wake of the Valerie Plame/CIA leak investigation, during which New York Times reporter Judith Miller was jailed for contempt after refusing to identify a source. The effort lost steam after the WikiLeaks scandal in 2010, but now, with White House backing, the bill has been reintroduced. But whatever the merits of a shield law, enacting one in response to the AP subpoena would be a feel-good gesture that makes little sense.