An affidavit suggests why FBI agents posed as agents of the Israeli intelligence agency Mossad to conduct the sting operation.

From 1998 to 2008, the complaint alleges, Nozette was a technical adviser for a consultant company that was wholly owned by the Israeli government. Nozette was paid about $225,000 over that period, the court papers say.

Then, in January of this year, Nozette allegedly traveled to another foreign country with two computer thumb drives and apparently did not return with them. Prosecutors also quote an unnamed colleague of Nozette who said the scientist said that if the U.S. government ever tried to put him in jail for an unrelated criminal offense, he would go to Israel or another foreign country and "tell them everything" he knows.

The complaint does not allege that the government of Israel or anyone acting on its behalf violated U.S. law. In Jerusalem, Israeli government officials had no immediate comment.

The affidavit by FBI agent Leslie Martell s