Publish it like this: Request: http://myblacklist.com/?firstname=Fffff&lastname=Llllll&company=Ccccccc http://myblacklist.com/?firstname=Fffff&lastname=Llllll&

Publish it like this: Request: http://myblacklist.com/?firstname=Fffff&lastname=Llllll&company=Ccccccc http://myblacklist.com/?firstname=Fffff&lastname=Llllll&comp... Possible replies: {"status":"not found"} {"status":"record found", "record_id":12345, "note":"Request more info at: retrieve-record@myblacklist.com"} In "record found" case - allow requester to sign legal confidentiality and non-disclosure form before allowing to see more details. This way no names are published open and you acquire a bit more of protection. This is sort of becoming your own "credit bureau". Talk to lawyers still about it.