It's not about trying to determine if the traffic is i2p or tor by its port or contents. It's about running a copy of the client and logging who it connects to.
When you have nearly limitless funds and servers everywhere already, it becomes a lot easier to insert into the network and start looking around.
Then when you couple that together with a series of corporations that can do that, and they start sharing data.
Then you change the legal landscape so they can just kick you off your internet provision because you are connecting to I2P nodes. It's kind of like entrapment, but legal.
