I suppose to include here, you are often nost just trusting the relay hoster, but often CloudFlare for observing your plaintext traffic, IPs, and so on, or whatever datacenter/hosting provider the relay owner is using as well. I can't imagine most relay owners are hosting their relays from their home networks.
Discussion
These are often American or European companies, and therefore less likely to be a threat to me, personally, than individual nutjobs.
Pick your poison.