All the the thiefs need to have done is brought the numerous airfield guides that list all the most airfields and majority of private airstrips in the country Pooley, AFE and Lockyear.
Also i can do an internet search and within a few minutes find sites listing all these airfields some of these sites are from fellow pilots or LAA struts listing there members airfields..
Also a pilot has put on the net a KMZ file pin pointing the majority of private strips on Google Earth.