Super Police

For those who can't read this, it says:
"If you see a train being vandalised called the British Transport Police on blah blah blah".
Then there's a picture of a helicopter.
What the fuck?
Are they suggesting that if you see someone slashing the seats then they'll jump on a helicopter, Mission Impossible style, and fly into the underground to stop the hoodlum?!!!
Are there police helipcopters constantly on patrol to dissuade vandals?
Perhaps this is why it is so expensive to ue the tube...