Last Saturday night, a 15 year old boy was shot dead by a police officer in downtown Athens, this incident sparked nation-wide unrest in Greece. The background info is here, http://www.ekathimerini.com/4dcgi/_w_articles_politics_100002_08/12/2008_102842, and live TV could be viewed here http://netgreece.net/alter_live.html or choose your own channel.
Basically, the day-time demonstrators are young people including students who have discontent with government policies; the night-time trouble makers are true criminals who destroy properties and loot merchandise. Apparently, the police on some isolated cases have used excessive force towards day-time demonstrators, but have not found any effective measures to deal with the night-time criminals.
In Greece, the police is accountable for their wrong-doings, the officer who killed (accidentally or not) the 15 year-old is in custody and will be investigated for possible charge of murder and illegal use of weapon. The Interior Minister and his deputy chief immediately submitted resignations (although not yet accepted) to Premier Karamanlis.