@p well companies like psychz for example, they provide cheap "budget" dedicated servers, right? when you rent hardware from them, they will assign you a /31 (or a /30, /28, whatever). they will take your account information and publish it to the whois of the IP. so if you have your billing address on your account and that happens to be your house, well i think you can figure out the rest. regular customers and businesses. apparently a lot of ISPs do this