What's going on? Is namecheap.com selling my data (the same way that water companies used to sell a list of "new connections" to churches and salesmen)? Is someone watching for changes in the DNS entries? My domain name is obscure and not in use yet, so I don't know how anyone would even know to look for it.

Is there something about the technology & workflow that I don't know yet?

Obviously, I know that my info is in the DNS entries, even on a parked page (and I refuse to pay for "private listings" on principle), but how do these leaches know about it in the first place?