Difficult to believe, but it happened. The twitter account of the Federal Belgian Crisiscentre got hacked tonight and was sending out some spam messages. Well at least they apologized (Dutch):

Sorry voor de spam. Klik niet op de link. Paswoord is veranderd. Goeienavond ;)

— CrisisCenter Belgium (@CrisiscenterBE) January 20, 2012

We can only hope they learned from the incident, can't imagine that during a real crisis the 'bad guys' would control their communication.