Golden Dawn has been getting steadily more popular lately, and they have quite the motivated voting group. It's believed they could double or triple their representation in parliament if new elections are called, and someone is getting nervous.
Over the last few days,
Golden Dawn MPs threatened to walkout, possibly forcing new elections.
The Special Forces Reserve Union, which I guess is retired military, called for the government to step down. Though some think they called for a coup

Golden Dawn MPs have just been arrested en masse for running a criminal organization. Like the mafia I guess

Golden Dawn has around 15%-20% popular support, and a significant number of them will become very angry over this. Just a few percentage of the population out numbers the police and military, and Golden Dawn is much stronger in the police and military than general population. Then there are the non Golden Dawn supporters who aren't amused about these questionable arrests. Fun times ahead !