This may account for some of the game’s server issues over the past few days; countermeasures are still being worked on. The game has also had a minor patch to address other technical issues and bugs, so players should have a better Stormblood experience waiting once they log on if the DDoS attacks don’t make it unplayable. (And if they get through the queues, but that’s just to be expected.)
Source: DDoS attacks, Hotfixes; thanks to David for the tip!