I don't know why you were downvoted, I had the same question. Port 6667 means to me that it's plaintext, but it looks like hidden services don't have the "exit

I don't know why you were downvoted, I had the same question. Port 6667 means to me that it's plaintext, but it looks like hidden services don't have the "exit node leak" problem clients have with plaintext protocols because they're not involved in the traffic with the hidden services. It looks like the traffic's encrypted all the way.