We haven't heard much about the Madoff clan the past few months. That's not because the feds grew bored and decided to give up. They've been quietly assembling a case against Bernie's brother (Peter) and two sons (Andy and Mark), and may eventually charge them with tax fraud for using Bernard L. Madoff Investment Securities as their "personal piggy bank":
The exact nature of the potential tax violations isn't clear. Tax-fraud cases often involve the alleged failure to declare income or making false deductions, such as classifying personal expenses as deductible business costs.
If Peter, Andy and Mark used their corporate American Express cards the way Bernie did, it's safe to say it's an open and shut case.