SMITHTOWN - Tax season is in full swing and authorities are warning of scam artists who file phony returns to steal people's refund checks. A Smithtown couple says it happened to them. Chris and Mary Madonna say their information was stolen and a scammer illegally filed their returns. The crook got away with a $9,000 refund check. The Madonnas are not alone: the IRS says it discovered 262,000 fraudulent refunds in 2011, amounting to $1.5 billion in stolen refunds.The IRS says taxpayers should watch for scam e-mails that ask for personal information and use strong passwords to protect their identities online. The agency also advises citizens to file their taxes early.