I didn't reply to the e-mail mentioned previously and today (May 10th) I recieved a letter from a collection agency, Simons Muirhead & Burton. It says they are instructed by Getty in respect of a "possible" claim for copyright infringement. It says Getty has written previously and made me aware that I "may" be in breach of copyright by using pics they have exclusive rights to. It says there is a seperate form which details their offer for settlement, the amount is specific to the "apparent" infringement. Then goes on to say if I agree to their terms I should complete the form within 21 days confirming my acceptance.