As they informed us with one message, a DDoS attack is currently underway on two government websites, which appear to be offline at the time of writing.
Sites are in the domains primeminister.gov.gr and startupgreece.gov.gr.
Both are subdomains of gov.gr where almost all government websites are hosted.
According to the Powerful Greek Army, the DDoS attack was carried out (and apparently continues to be carried out) in cooperation with Hellenic hacking team with them @PhantomNations
Below you can see the screenshots shown by DDoS 
In our question, why did PGA respond to these attacks:
To see how good protection such popular government sites have, they have not at all.
And one screenshot from startupgreece
