This is not how the law is applied to packet switching.
If it was store and forward then maybe just maybe law enforcement would care, but anybody smart enough to set up an I2P node to research it and who tried to track where packets from from would first see the packets originate from their own local node at 127.0.0.1, then in the I2P console they could see that packet came in via an active half-tunnel from their own end interfacing with the endpoint node of the other side’s half-tunnel, and they would know that node has no idea what it’s sending (just like their ISP)