Female Stalkers: Advice needed

I have a female whom I had children with and the realtionship has failed to work out.

What scares me is the obsession she always had over my personnal life then and now.

She used to hack into my computer, track all my post on several websites. Somehow find a way to locate me on forums despite changing passwords and names.

She hacked into my emails, wrote ones herself to people inmt name, would PM family members on FB and try to turn them against me.

The women is a nutjob.

AND WONT STOP. despite being seperated for over a year this women still contiunes to seek out my posts, hack e mails, even send disparaging faxes to prospective employers and landlords.

Just on and on. The problem is she has custody of my kids. And I cant see them if I say anything she does not like on any forum anywere.

Its blackmail, stalking and general BS

I dont live with her, I dont see her, but she just wont stop with the obsession.

F-me ,any suggestions?