Our site was setup to have the default new user role be an author instead of subscriber. My intention was to have people post pictures here on their own posts. We had some blog spam that was taken care of. The default user role was changed back to subscriber, which does allow comments, but not posts. This is not a hack, and your information does not appear compromised. Nobody forced thier way into the site, blog spam is a part of blogging and isn’t serious.