... Yes. How do you think Ramza and his goon squad get into peoples' accounts?

To steal accounts you have to get information that allows you to gain access of the account. E-mails and passwords can get you into an account.

Some people make passwords that are very easy to guess or easy to generate. This would be cracking or brute forcing.
Some people fall for phishing, which is tricking someone into giving information. Claiming your an admin or making a fake support site are types of phishing.
Some people run malicious programs that access information on your computer or log keystrokes. Ramza used this one on a few people.
Sometimes information is leaked from Graal's account database or support center. This has happened a bunch of times on Graal.

You can get direct control of the Graal account and then change the password, or you can get control of the e-mail and have the password changed.