The real risk when a forum gets hacked depends on how the administrator of the forum stores passwords. When you log into a system, the server will "hash" a password. This means to create a mathematical algorithm. Now, it is possible to easily crack a hash so that hash is often salted. Salted means to toss in random characters & data. This makes the hash almost impossible to crack. So if the hacker of the forum does a data dump of the information the email will be in view but the password will not be.
Why does this matter? Users tend to recycle passwords & email. So the email and password you use to log into this forum are probably used for other accounts. When the hacker dumps this data he does so in a place where other hackers can see it. The first thing they'll do is try other social media, email accounts, etc. In a very short time they have a great deal of your personal data & can use it to extort whatever from you. After the data dump from
Ashley Madison was released people reported being sent threatening messages to pay up in bitcoin or have the public information be released and destroy you. Believe it or not, there are lots of men who are stupid enough to sign up with an account that identifies them. Lulzsec hacked Pron.com in 2011 and there were a number of government & military officials who signed up using their official email. Information is the new currency.
There is speculation that certain forums (not this one) do not encrypt their passwords at all. The result is the moderator of that forum can see your email and password in plain text. This is more common than you imagine as many web administrators have limited to zero security skills. That is why you often see data dumps which contain the password in plain text. These forums are canned products like Wordpress is. They need to be constantly updated or they're the internet version of Swiss cheese.
