Yes, we're aware of this leak from last year and we initiated a forced password reset on all accounts last year. Our forum uses email authentication to prevent authorized access to someone's account. This means even if someone has your password, they can't use your account here without also having access to your email address. As long as it's not the same password, the person wouldn't be able to do anything.
For further protection we offer two factor authentication via Google Authenticator on your Android or IOS phone which you can add for free via our Upgrade page.
As stated above, we do not delete accounts, but we can close it if you like.
I'm sorry to say but no website is safe from being hacked. Dota2.com, all Funcom game forums, linkedin.com were all hacked in just the last 3 months and all user info was leaked online also. Sony was hacked two years ago. If billion dollar companies like this get hacked regularly, there's very little hope for small companies like ours.
I'm sure on that site where you saw the leack you can see a list of websites and you'll see every one of our competitors listed there also because I've checked, all have been hacked in the last 2 years.
If you don't want your info leaked on the internet, you'll have to stop using the internet. Sorry, but this is the world we live in now and why it's so important to use a different password on every single account you have.