They have no Heavens-Ward against it.*
Square Enix has, repeatedly, been forced to deal with DDoS attacks coming from an indeterminate third party since June. And they certainly aren’t showing any signs of stopping soon. As a matter of fact, they’ve gotten more difficult to deal with over time, moving from Final Fantasy XIV’s servers to upper-tier internet service providers. Per the blog post on the game’s North American site:
As previously announced, we have confirmed that since mid-June, a third party has been targeting the FINAL FANTASY XIV game servers on the NA data center.
Until now, we have been implementing defensive measures at our own facilities to combat DDoS attacks against our FINAL FANTASY XIV game servers, and have been able to keep the impact to services at a minimum.
However, since July the attacks have shifted away from the FINAL FANTASY XIV game servers and the target has changed to focus on the upper-tier internet service providers (ISPs) that are required to connect to the data center. These attacks to the upper-tier ISP network are causing lapses in communication to the game servers, giving rise to instant disconnects during logins.
Since the problem has long since exceeded their ability to cope with it, they’ve teamed up with those upper-tier service providers to combat it. That said, such cooperation is no guarantee against an attack.
For those crotchety old types, I’ll explain what a DDoS attack is in the broadest understandable metaphor possible. You see, the internet is like a series of tubes**, and each one goes somewhere. A DDoS attack seeks to clog the specific tubes to and from a given place. It does so by blasting the servers with a large amount of data (literally anything), causing the servers to be overwhelmed.
*I’ll see myself out
**I’ll never let this go. Especially since this is, in fact, the closest that explanation has likely ever been to being useful in the slightest.