I am not an internet expert, but looking at this simplistically I fail to see how using a VPN on subscription can protect the user from being identified. Clearly it adds an extra layer of obfuscation but the very fact that you are subscribing means they have your details, and when you use them they have your IP address, so presumably against a court order they could see who was going through them to a particular site at a given time.
Correct me if I'm wrong. I'm not paranoid and have nothing to hide but I work on the basis that nothing on the WWW is totally anonymous if someone is prepared to invest the resources to track you.
Edit :
Coincidentally, I just came across this article :
WTF: The internet's secretive hangouts | News | Sci-tech | Mail & Guardian
Sites such as the Hidden Wiki can only be accessed through anonymity networks like the Tor web browser. Tor, or the Onion Router, is an open-source network that directs internet traffic through a worldwide volunteer network of servers to conceal users' locations and identities. Tech activist Karen Reilly, who works on Tor, told the M&G that "one of the reasons to set up a dark net is to avoid detection. Measuring murky address space is a challenge. Some of the best examples of Hidden Services are not published, because they serve as a secret meeting place for people who need a safe space for political activities and support groups."
The use of Tor by dissidents in Ethiopia was disrupted in May this year. In a posting, Tor noted that the Ethiopian Telecommunications Corporation had been using a "deep packet inspection [a sort of finger-printing of encrypted information]of all internet traffic … We have previously analysed the same kind of censorship in China, Iran and Khazakstan."