Developers at ArenaNet are asking all those players who have not changed their passwords for Guild Wars 2 since September 2012 to do so on February 7, in order to increase the security level of the MMO.
After a security breach, the team created a new system that blacklists a number of passwords that were used in past attacks. The new system has worked well enough to persuade the company to extend it to the entire player base.
The official blog post
from ArenaNet states, “after changing your password, you’ll be confident that your new password is unique within Guild Wars 2. However, your password only stays unique if you then don’t use it for other games and web sites, so please, if you value the security of your account, use your password exclusively for Guild Wars 2.”
ArenaNet previously promised that it would increase both security and stability for Guild Wars 2.