From an interview that Spiegel did with Greece’s Foreign Minister Dora Bakoyannis…..

SPIEGEL: Why have the police reacted in such a restrained and passive manner?

Bakoyannis: The police have not reacted passively, rather they have sought to de-escalate the situation. The government decided that it would rather accept material damage than new casualties and victims.

Earlier in interview Spiegel characterized the material damage this way..

The protests have been more than just an outpouring of anger and grief. In Athens alone, block after block has been devastated.

Accepting this kind of damage in the name of de-escalating the situation strikes me as paying the Dane-geld to a bunch of punks.