Alan,
It's obviously a complex topic, but common consensus on using images on the Internet today is that if you are using someones images (IE: images that they own or have rights to) without their permission and for some commercial gain then you could likely be sued by them for copyright infringement. Similarly if you used their image on a poster which you were giving away for free they might be able to show damages in that some of those people may have bought a poster from them and thus you have deprived them of income from their intellectual property.
Now suppose I were to post an image of a famous modern-day painting here on the site to talk about how much I like the painting. Is that copyright infringement? The courts have said not. Not unless the artist can claim that my fair use of his image is somehow causing him monetary damage (in fact the reverse is probably the case as my promoting his work will lead to more sales, fame, etc).
The problem with most historical photos is that no one can really say with certainty (from them being on a website) who the rightful owner of those photos is. Or even whether they have fallen into the realm of public domain. Of course those considerations are moot based on fair use anyways. They only come into play if the images are being used in a way causing damage to the rightful owner.
As this relates to the pirated figures discussion obviously a copied figure sold to customers via the Internet, shows, or eBay causes direct and undeniable harm to the creator of those figures. On the flip side, ask Taesung if he minds when images of his figures are used on forums to discuss his figures. Probably not.
Cheers,
Jim
