Listed as "Network Technical Difficulties", Square Enix released a statement about the recent network problems they've been experiencing in Final Fantasy XIV. These issues have been happening since June 16 and continue to this day. Upon further examination, they're learned that it has been a DDoS attack from an anonymous third-party specifically targeting their North America data center.
A DDoS attack is a form of cyber attack, standing for Distributed Denial of Service, that specifically floods a server in an attempt to increase the server load, causing slowdowns or outright halting a service or website.
Because of this attack on Final Fantasy XIV, game servers, network equipment, and network connections are malfunctionings, which translates to forced disconnections and login difficulties.
A DDoS attack is mostly harmless, in the sense that it's not traditional hacking, so no personal data is vulnerable, but that doesn't stop it from being debilitatingly annoying.
Square Enix is working on the problem currently, but they're having a bit of an issue:
"Our technical staff is taking every possible measure to address this issue but the attack is still continuing to take place by changing their methods at every moment. We will continue to monitor and work on recovery from every possible angle."
This likely means someone is taking time out of their day to impede the service. Considering there's no data to be stolen, the amount of work put into this attack makes little sense, but if more comes of this story, GameZone will have an update.