Health care is a tempting target for thieves. Medicaid doles out $415 billion a year; Medicare (a federal scheme for the elderly), nearly $600 billion. Total health spending in America is a massive $2.7 trillion, or 17% of GDP. In 2012 Donald Berwick, a former head of the Centres for Medicare and Medicaid Services (CMS), and Andrew Hackbarth of the RAND Corporation, estimated that fraud ... added as much as $98 billion, or roughly 10%, to annual Medicare and Medicaid spending - and up to $272 billion across the entire health system. Federal prosecutors had over 2,000 health-fraud probes open at the end of 2013. A Medicare strike force", which was formed in 2007, boasts of seven nationwide "takedowns". In the latest, on May 13th, 90 people, including 16 doctors, were rounded up in six cities - more than half of them in Miami, the capital city of medical fraud. Punishments have grown tougher: last year the owner of a mental-health clinic got 30 years for false billing. Yet the sheer volume of transactions makes it easier for miscreants to hide: every day, for instance, Medicare's contractors process 4.5m claims. In this context the $4.3 billion recovered by fraud-busters in 2013, though a record, looks paltry. Some criminals are switching from cocaine trafficking to prescription-drug fraud because the risk-adjusted rewards are higher. This is the medical world's "dirty secret", says John Holcomb of the Texas Medical Association. Everyone talks about it in the doctor's lounge, but few complain.