hehe, I kinda stumbled uppon the same thing, one was herrasing me, claiming my domain, which I've had for over a year belonged to him... (it was ugly) Anyway I didn't wanted him showing up on my home address, so I contacted
dk-hostmaster requesting them to remove any billing/register info when searching for my domain, unaware this even prevents me from changing anything without a written accept, signed by me, that things should be changed..
for comparison:
my domain another domain