According to the latest Mike O’Brien’s post on the official GW2 site, the only way to keep your account save is by using a unique password for any account you care about!
The basic truth is this: hackers steal game accounts because they already know the account name and password. They know them because they stole them (via security breaches or spyware) from another game or site where the person used the same account name and password.
If you’re not sure how to protect your account, there are some ArenaNet tools that may prevent hacker’s attack:
1. Email Authentication: When you first login, we ask you to validate your email address. After that, whenever you attempt to login from a new location, we send email asking you to approve or deny the login attempt.
2. Password Blacklisting: We’re building a blacklist of all the passwords that hackers are scanning for — it’s already at 20 million passwords and growing — and we’re preventing new customers from choosing any of those passwords. (The blacklist contains passwords only, not account names.)
More details you can find on the official Guild Wars 2 news page.