Scrptkiddies with a botnet pingflooding servers for attention.
People getting mad / authors writing about them / forum threads being created about them = attention
If nobody gave them the reaction they wanted they'd have little purpose to continue, script kiddies are all the same.
They took it too far anyway, they sent a bomb threat to John Smedley, which has resulted in the FBI getting involved.
http://thegamingground.com/2014/august/psn-gets-ddos-attacked-bomb-threats-and-the-fbi-manhunt.html