We run a website that has a number of public content makers that represent the public faces of our project. One of the people has a previous online stalker who has found her at our site and has immediately started commenting on her posts and content.
Aside from tracking and blocking his IP what sort of technical solutions can I be implementing to help alleviate the situation?
There's not much you can do besides restricting access to information (eg: name, phone-number, email, etc.).
For example, your site could just not display anything but firstName lastInitial and the email (if necessary) to unregistered users, or registered users with insufficient permissions. Permission levels and information displayed could be tweaked according to your needs.
But ultimately it's up to the person posting content online to be careful with what they show/publicize on your site and elsewhere on the net. It would be useless for you to restrict access to information, but then she has her email and if you Google the email (or look her up on facebook) and her information is there.
Honestly I am a bit surprised by the way people feel free to post their email, real name, phone number, address, etc. online nowadays. I come from days where people liked to be anonymous online; and up until now a Google search for my personal email still comes up empty.