I'll reproduce your reply from the BHW thread to save readers having to go back and forth.
Originally Posted by Andrew at BHW
Thanks kvmcable. Seems we're both fans of data however my conclusions here are not merely opinion. There is simply nothing to be drawn from the data you have.
Once we exclude domain sales or websites without IP info, we're looking at about 1,000 distinct IPs. Over 95% of these only have one seller. This becomes over 99% once we relax this to permit 2 sellers on an IP (hardly a coordinated team).
This leaves just 10 IP addresses which are more widely shared. A deeper dive indicates they belong to major hosting providers such as GoDaddy, HostGator, Yahoo, ThePlanet and RoadRunner which is perfectly normal. Furthermore,the sellers tend to be incredibly different in terms of types of site being sold - by age, sale price, wording, monetization, technical framework etc - and Flippa profile (bid/sell activity, IP footprint, registration dates).
To this end, it seems incredibly arbitrary to be taking action against these users given the acutely low signal to noise ratio here ...
Where we do have strong evidence we take firm action. To this end, don't be expecting the shill bidder back any time soon.