Geeks always think they will trick the system by being smart. They fail. It's no different when intensely brainy women take up escorting over the Internet, like Stanford Law graduate Cristina Warthen, in court this month facing federal tax evasion charges. As sophisticated as the sex trade is, there's still no magic solution for how to hide the money. The Feds claim Warthen hid cash in a safe-deposit box, her apartment, a storage locker, and even law-school textbooks they found in the trash. I've watched clients nerd out over this on message boards for years, trying to come up with the foolproof plan. There isn't one.The under-the-mattress route. The plus side: You'll avoid getting caught up in antiterrorism sweeps. From loading up throwaway debit cards at Walgreen's to starting offshore corporations under proxy boards in Nevis, there's just no way to handle thousands of dollars in cash without straying into money-laundering territory. The risk here is that large stacks of dollar bills can be found if your home is searched. Not being Al Capone. An escort who finds an understanding tax attorney could just pay the Fed what they're due — or at least, close enough. Warthen tried this route. It, too, failed her. And why? Living smaller. Her Benz and her pad didn't add up for someone who only declared $13,000 in annual income. As one message board client who claims to have known Warthen wondered, how different might this have gone down if she'd just driven a Honda Accord? Watching the weakest link. No matter what elaborate James Bond ideas you've got, there's always a coworker crazier than you who, when she gets into her own trouble, will out you. It wasn't a client sting or even a tax audit that brought "Brazil" to the attention of the lawman: it was a careless Orange County madam. When she was picked up by her own local law enforcement, that led cops to investigate Warthen. That's why they were sitting in wait outside of her apartment, and that's why they found $2,400 in cash tucked into law books thrown out with her trash. (Photo by RM Studios)