Run fake onion servers to study behavior of malicious clients
Run onion-servers that don't advertise services in any way, so that if some entity that wants to uncover onion-services by trying out many onion-addresses can also accidentally stumble on to them and thus be studied and distracted from real onion-services. This can of course be done by having the decoy servers assume multiple onion-adresses par server, so the chance of catching a malicious client is higher.
Edited by smoutwortel