Users who just had all their favourite bittorren trackers shut down
To survive political will to crush them, encrypted overlay / messaging networks need mass popular usage in the millions of people and up. That's traditionally come from email, social nets, torrenting / file / web services, video, and chat. While overlay nets are certainly not currently immune to GPA's and such, they're reasonably ok for more benign uses, and the above uses and users are growing within those nets. In the example of copyright holders grokking their BT client for IP's and hashes to send to ISP's and courts... those trolls are going to have a *much* harder time trying to shut .i2p's and .onion's, and especially users of decentralized p2p model client apps over overlay nets.