After the website of the Greek Justice Ministry being hacked by Anonymous, they targeted almost all Greek government websites. The reason is to support people-powered uprising in Athens. They have taken down the websites of Greek Prime Minister, the National Police, the Ministry of Finance, the Greek Parliament, the Minister of finance Evangelos Venizelos (personal site) and some more. Anonymous try to support the Greek people that react to the measures of their government to avoid national bankruptcy. Greeks appreciated Anonymous actions and they felt that they are not fighting alone.
Source: [AnonOps]
Anonymous targets Greek government websites