Without expressing any particular opinion on this topic, I merely offer the following datapoint.
Yesterday, I took a photo of George Bush and uploaded it, and linked it into the article. Someone else at the same event (small world) did the same, changed the photo in the article to his instead of mine. No problem.
But, his photo, when I clicked on it, appeared as a vandal photo. That is, the thumbnail in the article was fine, but the photo underneath was bad.
At one point, I checked the history of that photo, and all revisions were from the same person, and all were evil. However, this does not seem to be the case in reality... the reality is, there was a caching problem... (?)
The poor other fellow almost got blocked by me for vandalism, it's just that I usually try not to block people if I'm the least bit confused, because since it is me, people will take notice and I'm the last person to want to violate any rules. :-)
When I got home to research it more, (a) I still saw the bad photo on my laptop, which had *NOT* looked at this article before, ever. This implies that the caching problem was not a local browser cache! and (b) the history now looked accurate, showing the original, the vandalism, and the fix.
Anyhow, my sense of things is just that it's hard for editors who are trying to combat photo vandalism to figure out what is going on.
--Jimbo
p.s. Separately, my wife called me while I was driving home, and she had looked at the article on her computer, and in her case she saw the goatse.cx image there. this was not a caching issue nor was it the same issue at all, but just routine vandalism. I am more convinced than ever now that we need a "soft protect" mode of "slow publishing" for certain very very popular and very very important articles.
By "slow publishing" this is not my idea, but one that has been discussed as far back as when I was in Berlin at least... the idea is that the latest version of an article is only shown on the main url once it is 10 minutes old, or if a sysop deliberately clicked on 'publish now'. This gives a rolling window to combat stupid vandalism, rather than having it on the site for even 3 minutes.