The answer is "Fraud"
Fraud can classified into different kind of frauds. But the basics are civil or criminal.
In most of the cases, fraud is prosecuted by the victims in the U.S. through local courts (as the victims' main purpose is to recover money from the loss).
In criminal fraud, the government will usually have the authority to prosecute. But they won't prosecute unless the case is big enough (like million of dollars loss, injuries, etc.)