A reason to not commute by train

The BBC pointed out about some "human graffiti" that's spreading across the rail network.
Could this be coincidental, or is the London Underground plan to use anti-flu spray on the Tube related, I wondered.
Ben put me right:
Anti flu spray? They need an anti turd spray. Yes, I'm talking about a spray which is effective for eight hours when used in an enclosed space. A spray that will turn shit into dust so quickly and effectively that it works as the shit leaves the arsehole. Our man will be operating like a vacuum cleaner in reverse. Staff can then come and sweep up the mess and no harm is done.
The trouble is that people will be amazed by this powerful spray, they will want to try it out. Bored youths will be riding the last train home with their greasy tracksuit bottoms around their ankles, trying to blow clouds of dust in each other's pasty faces. The problem of course will be that one of them, the slackjawed, coldsore encrusted one who smokes on trains and buses, may have opened a window, thus reducing the effectiveness of the spray throughout the whole train. Young people will occasionally find themselves shitting in each other's faces on public transport. Perhaps it will become like a twisted version of russian roulette. I hope I die before this day comes - peacefully, in blissful ignorance of the horrors that await Britain, and of an illness or injury entirely unrelated to face shitting.
While we're at it, did anyone who watched Children Of Men think of the positive of no more children - there wouldn't be the school run jamming up our roads throughout the year any more. That's got to ameliorate the end of the human race somewhat...