When a leaking drainage pipe from a slurry store pollutes a stream or a river and causes off the fishes and invertebrate life for even a single kilometre the Environment Agency investigates and prosecutes and the farmer has to pay up thousands of pounds in fines and costs..
When a leaking drainage pipe from a laboratory handling seriously dangerous viruses pollutes the countryside, causes the deaths of thousands of animals, devastates the food industry and costs thousands of farmers thousands of pounds the Envirionment Agency does nothing.
That's one reason why a thousand farmers turned up for a mass meeting at the Royal Welsh Showground last night desperately worried about the crash in their incomes and wondering about things like double standards. What has happened to the principle that the polluter pays?
There's not much the farmers can do. The NFU is going to pursue a claim for damages from the laboratory owners, the government, but has been told that could take three years and a lot of money to drag its way through the courts.
Direct action will not lead anywhere. Brynle Williams was shouted at from the floor last night for calling off the fuel protest "too quickly" - that is, presumably, before the army was called in and the country descended into a real crisis.
Anyway the law has been changed. That couldn't happen again. Farmers could boycott the marketplace, but that would only succeed if everyone did it.
There's another meeting at Abergavenny on tomorrow. Get used to it. The industry has been in crisis for decades. There is no sign of it coming to an end.