AFAIK Tor isn't secure so far (exitnodes). Created by the US gov. IMO just another honeypot. Today, the tracking methods have progressed so much that the IP address is becoming increasingly important as a key feature. Based on certain features, such as the cookies, installed browser add-ons, screen resolution, standard language and others, users can be almost uniquely identified. Why PP doesn't provide cascades? They say they do. But I don't use it.