Something similar happened a few years back in the Scillies, when the Cita rammed the islands and dumped its containers:
The islanders grabbed everything they could. There are photos of boats full of golf bags, car tyres etc... all kinds of things are carried on the container ships. Most of it will be written off - interestingly in the case of the golf bags calloway bought most of them back (paid salvage costs to the locals I guess) to prevent the bags getting into circulation.
If you do salvage something and report it, the owner is obliged to pay you something or write it off and give it to you, so either way you can make something from the wreck. The trick is of course to report it. If you don't the reciever of wreck (a very nice lady from Southampton) can pay you a visit with the police and search your premises.
I can understand why the police get the hump, as a lot of stuff will never get reported, and it will cost them a lot of time to chase it all up (photographing people / car registrations etc). If the rest of the containers go over then it will be a serious salvage bonanza.