In my case, my ex-wife called me at work and was bawling her head off. Said a letter from the IRS had came in saying we owed them $40,000 because of a mistake on our return about child care expenses.It's not just the KGB, err, IRS. A friend's dad was a veteran, and was deemed due some kind of VA cash benefits (dunno the details, but I think it for was a service-related illness). The VA successfully ran out the clock on him, and he died before the VA came across with the money. My friend had used some of the money from the VA (which had been deposited into his dad's checking account) for his dad's "final expenses" when the VA, having finally realized that they had successfully screwed another veteran, caused Omar Bradley to do one more rotation in his grave, and yanked the money back out of the account.
I didn't even make close to $40,000 back then. Subsequent phone calls to the IRS office in OKC with a line by line explanation of my return showed that the IRS actually owed me one dollar more. I always rounded up in their favor was the reason.
They put a lien on our home, checking and savings accounts. After hiring a lawyer we couldn't afford and having to repay him in installments for years, we got the IRS to pull the liens and clear us. No apology, no offer of reimbursement, it was just a story of so sorry about your luck. The Lawyer said he would sue, but how do you sue the IRS when you can't even afford a lawyer to do it? $10,000 later we paid the lawyer in full for taking our case.