The Guardian has a report of the BBC using a photograph they found on flickr for commercial purposes, in contravention of the Creative Commons terms under which it was published. Given that it was only pure conincidence that the photographer noticed this particular breach, it makes you wonder how often this sort of thing happens. Flickr is all well and good as a ready-made gallery site, but if you use it to store full resolution copies of your photographs, then no matter how restrictive a licence you apply to them, it would be very difficult to prevent unscrupulous or, to give the BBC the benefit of the doubt, careless use of the photographs for purposes specifically excluded by the CC or copyright terms, unless you make sure that you only allow friends and/or family to download the originals.