BH Williams wrote:
Perhaps these were the items in an advert for one of the electronics
retailers in the papers last week, which carried a disclaimer along the
lines of 'it is not yet legal to use these items in the UK'?

Yes. Ofcom have pretty much said they wouldn't take any action even
before the official change in rules, so that was the green light for
retailers to 'officially' sell what was easily available before anyway.

I am intrigued by this story, as I don't know how the PA system works.
The fact you could hear people laughing/swearing does suggest it wasn't
an iPod with an FM transmitter attached. For a start, they're very low
power - so looking for people near the appropriate receiver would have
been a good place to start looking for the 'offenders'.

Why did they announce the police would be at the next station, allowing
them to scarper beforehand. The clever solution would have been to
proceed, slowly, as if nothing had happened. Mind you, hindsight is a
wonderful thing!

Jonathan