Unfortunately, this sort of thing tars everyone with the same brush. It will never go away but it it will make the honest buyer/browser (the vast majority of us I hope!!) feel guilty/wary simply by just picking a product up and looking at it.
Now, with you going down the CCTV route, people will feel that it is a case of "look, but do not touch". Is that fair for the person who genuinely wants to see what he/she wants before purchasing? No, but one that we have to put up with is the answer I suppose. Certainly not your fault.
Sometimes, I have picked up something interesting at a show/shop but have always made an effort at not looking as if I was indenting to keep it but rather to put it back just in case I thought that I was being "observed". You end up totally paranoid and that takes some, if not most, of the enjoyment of going to shows/shops.
What a shame that there will always be some small minded, cheapskate thief, that ruins it for the honest, fun loving boat builder/hobbyist.
Ron.