Posted By:
warshawlawNot knowing something exists is different than knowing it exists and also knowing how rare it is relative to other items. The former is detrimental to the collecting hobby as a whole for the reasons already discussed; the latter reflects a particular collector's opinion as to rarity which others may not share and which may or may not be accurate.
It is not necessary for a collector to publicly disclose what he or she owns; I am certain that Bob Lemke or the folks at Becketts (sorry, don't buy the book so I don't know who edits it) would keep the info on who owns what secret if a contributor asked. Someone really concerned with security could send in the item image in confidence.