A robot voice telling me they were the IRS and they had a "warrant for my arrest" for "defrauding the IRS".

LOL. Without even an audit first? Like the guy says, "that escalated quickly!" I didn't call back. If I had, I imagine some sort of credit card payment would have cleared up my little "defrauding" and "arrest warrant" problem. Too bad "attempted scam" isn't in the "Call type" popup menu below.