SWBKCB
I believe it came out a couple of weeks ago. There is similar advice for German citizens as well, so I expect it to be pretty Europe wide. There has been a number of journalistic stories doing the rounds re shackling and detaining people visiting the US who have not even got into the country, but been detained at entry port. I certainly will not be going there or even changing planes - though I do try and avoid that anyway after a bad experience at LAX.
Cheers
Mr Mac