You missed the most question. How is this trackable and thus enforceable? And the answer is as long as the items remain physical and in cash without corresponding electronic transactions linked back to an address or person, that is isn't trackable beyond how you initially got the money (usually from work). Afterward, that $1000 that I took out at the Indian casino last week, who knows if I gambled it, drank it, ate it, or put it in the Church collection box? See I'm real forgetful, so I never have my casino loyalty card or my credit card with me so I have to pay for a lot of things in cash.