> For large values of cash, yes they can... No they can't, unless they have taken special measures (e.g. surveillance[1]) which are invariably resource-intensi

> For large values of cash, yes they can... No they can't, unless they have taken special measures (e.g. surveillance[1]) which are invariably resource-intensive. If a $100 turns up in a Miami drug dealer's wallet, there's no way of tracing it from the ATM is was issued from in NYC a month earlier. Cash does not leave a trail of breadcrumbs leading back to every wallet it passed through. Bitcoins, on the other hand, are traceable by default. Users have to make an effort to cover their tracks using a laundering service (vulnerable to compromise) or something like CoinJoin (potentially vulnerable to network analysis). [1]: http://www.kickstarter.com/projects/1460639069/follow-the-money-0 http://www.kickstarter.com/projects/1460639069/follow-the-mo...