... and houses and ATVs, etc...
Houses are tough- I know I just bought one. I had to prove where virtually every nickel I was spending came from (produce all the paper work for the sale of my previous house and produce bank statements for all deposits into my account for several months). I don't know this first hand but apparently any deposit into a bank account exceeding $10000 has to be accompanied with proof of the origin of the money. Of course it CAN be done, but I think only a brazen idiot would take the risk. From what I'm told this is a fairly recent procedure in the war against money laundering.