Quite a few BTP▸ as backup to the ticket checkers, the other morning.
I have edit the struck through text the quoted by me because it is unwarranted.
There are people who think it is their right not to have a valid ticket and will become very offensive to staff and it is not unheard of to become violent hence the Police. You cannot take a stereotypical view that because someone looks like a yob they don't have a ticket and the chap in smart suit has a ticket I have seen at Waterloo some very well turned out be-suited men become very agitated because they have been caught.