L’Aquila prediction: Seismologist Giacchino Giuliani predicted l’Aquila earthquake. Controversy?

Is an earthquake prediction possible??? In the l’Aquila quake aftermath, the italian scientist Giacchino Giuliani declared that he announced the authorities about the imminence of a quake in central Italy but he was not taken into consideration on reason that his research was not based on a scientific foundation.
The action he initiated one month ago involved cars with loudspeakers driven through the city and warning people on the desastruous quake was about to come, but he ended up sparking fury of the mayor who reported him to police. Furthermore, he was constrained to remove his findings also from the internet. Now, after the disaster struck, the italian premier Silvio Berlusconi, talked in a defensive way mentioning that “predicting a quake is impossible and there is no one who can tell when the next shake will come, in the next hours or days”
Giacchino Giuliani is a seismologist at National Institute of Astrophysics and he said that earthquake prediction was actually "based on the monitoring instruments which identified the point and allowed him to see the seismic precursor, a sign that the quake will be imminent within 6 to 24 hours".
On one side, regarding the fact the first shocks in the Abruzzo region were felt starting with mid-January and continued at regular time periods the prediction became in the end “inevitable” but on the other side it is difficult to control the masses without saying something with high accuracy.