The CIA is conducting an investigation to find out how widespread this sort of sloppiness is among its field agents. One thing that will probably come out of this is that the CIA agents thought that, since they were operating in an allied country, and with obviously cooperative Italian counter-terrorism agents, they did not have to use the kind of precautions meant to keep them safe in a hostile environment.
While European counter-terrorism organizations have been diligent at tracking, and fighting, Islamic terrorism in Europe, their political bosses are faced with media and public attitudes driven more by fear (of terrorist attack) and a desire to blame someone else (like the U.S.) This creates some strange situations. Like Italian courts trying to track down and arrest American CIA employees.
There was a major embarrassment at the CIA when it was discovered that Italian detectives had been able to identify and track some CIA agents because the agents had used a frequent flyer card to travel around Europe. That card provided enough information for the Italians to identify the CIA men as CIA employees. All this was going on because the Italian agents were trying to find out if the CIA was involved in the abduction of a Kurdish terrorist from Italy in 2003. Although this was done with the cooperation of Italian counter-terrorism officials, it was also done without the permission of the Italian government. That has turned into a major scandal in Italy, where fear of terrorists and anti-Americanism both compete for media attention.