Flickr; thing 9, thing 10 and tagging

Flickr. I'd had a go at uploading some photos onto another photo sharing website, but hadn't done much with Flickr other than browsing around. Following the instructions I now have this photo:

This is quite a curious photo (taken by one Peer Gynt it would seem). It's of a British designed (specifically Vickers-Armstrong Ltd.) tank called the Valentine, at a museum in Russia. The Soviet Army was supplied with quite a large number of these, not that they were overly impressed with them, but rather than giving this example Soviet markings, they've had a not very successful go at a British marked vehicle (it's supposed to be in a unit of the 23rd Armoured Brigade, but I haven't managed to find the book which will tell me which unit is referred to by '67').

The original photo is at:
http://www.flickr.com/photos/peer_gynt/3966916040/

(I've now found out more about the markings. It's supposed to be a Valentine of 'A' squadron, 50th Royal Tank Regiment - that's what the '67' means. There's even a photo of this vehicle in Tunisia in 'British tank markings and names by B.T. White'. The Liver Bird symbol to the right of the name really should be black on a white square and the 67 should, I think, be white on a black square, and the whole tank should be painted a sand colour, oh, and there should be a registration number, but apart that it's accurate.)

I've also set up my own Flickr account at:

http://www.flickr.com/photos/53094833@N03/

So, is Flickr of any use? Quite handy if you want to get photos of obscure British military vehicles or aircraft. I'm not quite so sure about libraries though; after all, someone has to create the images in the first place and then feel sufficiently generous so as to make them freely available afterwards.

One worry might be that one library has a member of staff who's adept at creating such images, does them in work time, or using work resources, and makes them freely available, until there's a change in the economic climate, and management goes kerching! [2] and sees a potential income stream. What's the legal position if I make something freely available, then change my mind a year or two later? Am I entitled to start charging anyone who's used my images? Should people who who have used my images be checking the legal position regarding specific images regularly? One for a lawyer I think?

Another problem is the tagging issue. By allowing people to chose their own tags, you could get the same image described in different ways. For example, in my Flickr photostream, I've currently got pictures of half-a-dozen british military aircraft, carefully described with both their name and the manufacturer's name. Except, that is, for the Spitfire which I though was a sufficiently iconic name not to need Supermarine before it. After checking in Wikipedia I could see there was a car called a Triumph Spitfire, which might have been present at the event where I took the photo. Should I go back and make sure that the manufacturer is in the tag as well?

Not that there are problems only with user defined tags. Library of Congress subject headings are a well known subject classification scheme, but they're incomplete, wrong in some cases, and subject to needless changes (like 'World War, 1914-1918' to 'European War, 1914-1918' and then back again to 'World War, 1914-1918' a year later when people in Washington thought to look at some history books).

At this point I'm going to have to admit that I don't know what the answers are (and probably apologise for having possibly wasted some of your time reading this).

[1] This supposed to be the sound of a cash till. I could also have used the Tom and Jerry image of dollar signs in someone's eyes, but that would have been even more difficult to do - I doubt that there are any free to use images of that around.