In the single largest crackdown in an eight-year campaign against health care fraud, the United States Justice Department charged 243 people on Thursday with $712 million in false billings to Medicare - the medical insurance program for the elderly - and Medicaid, which provides services to the poor.The alleged fraud spanned the country, from Miami - where 73 of the accused worked - to Houston, Dallas, Los Angeles, New York, New Orleans, Detroit and beyond. A sizable number targeted Medicare Part D, the prescription drug benefit that is the fastest-growing part of the huge program.Since it was put together in 2007, the government \strike force\ that focuses on health care fraud has charged more than 2300 people accused of falsely billing Medicare for more than $7 billion. Its efforts have been expanded with $350 million provided under the country's Affordable Care Act.In Miami, the owners of a mental health center allegedly billed Medicare for tens of millions of dollars for intensive treatment that actually involved just moving people to different locations. Some of them had dementia so severe they couldn't even communicate.In Los Angeles, prosecutors say, one doctor collected $23 million for more than 1000 power wheelchairs and other equipment his patients didn't need - and he often didn't even provide.And in Michigan, another physician allegedly prescribed unnecessary narcotic painkillers in return for use of his patients' IDs to generate additional false billings. When they tried to escape the scheme, authorities say, he threatened to cut off the medications, to which his patients were addicted.Some of the schemes were so brazen that FBI Director James B. Comey likened health care providers to \ATMs\ for the unscrupulous.\If you want to find criminals