Apparently the area around Wenceslas Square — one of the main city squares in Prague — used to be crammed with street vendors selling Czech sausages. But the neighbouring restaurants were unhappy about the stands cutting into their profits, and the city elected to remove most of them.
If you’re walking around and you stumble across a busy street vendor serving up deep-fried goodness, you have to stop and try it. That’s the law. Don’t look it up, just take my word for it.