Well, social media makes a big deal of this but its perhaps still quite a rare event although someone actually had their arse bitten last year. It was a big news story for a day or so but these snake-blocks are now being pushed out to people to retrofit.
If I were a conspiracy theorist, I'd say there were teams of people from the snake-block manufacturers driving around and shoving snakes in the drains!!
As I've written this comment, I realise I've just being robbed. I have a septic tank and soakaway as there is no mains drainage and so I have a closed system...I don't need fucking snake-blocks.....words will be had tomorrow....