No Smoking

On every flight I take I am reminded during the safety announcement that passengers may not smoke during the flight that smoking on board is an offence under international civil aviation law.

I am told that smoking in the lavatories is specifically forbidden and that each toilet compartment is fitted with a smoke detector which if you fiddle with it causes you to break even more civil aviation laws.

So why is it that an airline still finds it necessary to fit signage on the inside of the lavatory door warning passengers that they risk fines of £2500 if they get caught smoking of tampering with the detection devices?

But what I really do not understand is why on the aircraft I am describing an Airbus A321 which is less than seven years old this sign is placed immediately above the ashtray that has so thoughtfully behind the door by the aircraft builder.

And NO I was not flying with Ryan Air!