The problem is that fraud charge may be hard to prove, but may be much easier to initiate. And criminal investigation, even not resulting yet in a charge, may be rather annoying matter. For example, they could get (given a friendly judge) an order to seize all your computer equipment to look for signs of fraudulent activity. And keep "looking" for years, while you can't use them. And so on. If they arrange a cooperation of a friendly prosecutor, they can cost you lots of money while never getting to the court. Since they are paid by the taxpayers and you're not, you lose.