Years ago they actually sent me a check because they thought I should have taken a deduction that I didn’t. I didn’t want to get on a gotcha list, so I sent back a letter explaining that the deduction was not proper for my situation, and they responded that if that was the case, I needed to file an amended return. That was way more energy than I wanted to spend on this issue, so I just ignored the check… until the next year, when they mailed me another one with a tartly-worded form letter about the importance of promptly depositing it, and again the year after. At that point I figured if Uncle Sam is that desperate for me to take the money I’d indulge him. At this point I’m well past the statute of repose for any potential issues that created, so I think I’m in the clear, but I guess we’ll see.