They use many, many more ips to post the abuse, this is just a small selection.
I have sent similar emails to the 'abuse' email address I have been able to find for these ip networks, will they be able to help us?
I don't fully understand how your system for anonymity works, however I do understand why such a system is needed, there are many regions and people in the work who need anonymous access to communication.
However, our current problem individual is using your services to perpetrate the very oppressive, abusive behaviour that your system is designed to help fight. Please let me know if there is anything you can do.