How is it acceptable to sell service on a spammed IP addresses?
Tying assessments of trust to IP addresses through blacklisting is crude mechanism, and becomes more and more susceptible to type 1 errors as demand on the v4 address space reduces the time between address reassignment.
But it's an easy mechanism to implement, so basically nobody using it wants to admit it's flawed or learn to deal with it's unreliability.
Well, you have to remember that this isn't like DO is selling a stolen car or something, this is a bunch of third parties all deciding to reduce the value of that IP address. There's nothing inherently "wrong" with the IP address, just lots of shitty customer support.
Tying assessments of trust to IP addresses through blacklisting is crude mechanism, and becomes more and more susceptible to type 1 errors as demand on the v4 address space reduces the time between address reassignment.
But it's an easy mechanism to implement, so basically nobody using it wants to admit it's flawed or learn to deal with it's unreliability.