There isn’t really an issue with staff doing it, as they’re slightly more tooled up than the average punter. Whether it’s worthwhile is another matter, as there’s nothing to stop the feet being returned to the seat as soon as the member of staff’s back is turned. Perhaps I’m just getting too cynical as a natural consequence of getting older! But punters taking it upon themselves to lay down discipline is a no-no as far as I’m concerned, for numerous very good reasons. Things have certainly turned nastier over the last couple of decades, and this isn’t just perception as where I am the paperwork backs this perception up in terms of the number of fights and similar incidents on trains - some of this may be accounted for by trains having got busier, but the end result is the same, namely more bad people.