All this time, and technology hasn't solved this issue? Wasn't bitcoin supposed to be applicable here - anonymous transactions? Wasn't the internet supposed to enable humans to interact at will without censorship?
You can do the same with just cash.
If you'll pardon me, I think cash deposite below $1,000 should be none of the government's business without a valid, specific warrant. If someone wants to sell drugs, sex, or graphics cards on the side for cash, it's none of the government's business.