This doesn't stop people running private lotteries, though.
Take GM TV. This is a television channel that has a daily "competition". They ask a question, more than 10,000 people pay £1 to give them the answer, then they pay the winner £10,000. Here's today's question:
This is about the hardest one I've ever seen.
The scam is that because it's a question, this makes it a game of skill rather than a lottery. So that's alright then.
All GMTV's "£10,000 giveaway" questions boil down to the same one. They could save themselves a lot of time and effort if they just asked it outright every morning:
The correct answer is a.