They leaked all the username and password online through their official Facebook & Twitter account.
And approximate after half an hour the website of Union of Municipalities of Turkey (tbb.gov.tr) has been taken down by the officials due to unauthorized access.
According to Softpedia:
The hacktivists have dedicated this attack to Ali Ismail Korkmaz, one of the protesters who were killed by police during the Ocuppy Gezi protests. After gaining access to Union of Municipalities systems, RedHack created an account with Ali Ismail Korkmaz’s name.
The attack is also dedicated to Utku Kali, a Turkish soldier who faces 25 years in prison for leaking secret documents on the recent Reyhanlı bombings.
RedHack claims the Turkish government cannot prove that Utku Kali has leaked the documents.