Originally Posted by
SeriouslyLost
Perhaps I am unlucky. Or perhaps it's the multiple passports I travel on. Or perhaps it's because I only allow up to a certain level of questions before I tell them to sod off. Could be all sorts of things. I imagine it varies as much as any other thing when it comes to the individuals involved, but I do find it peculiar that I only ever have problems in the US and with US CBP and TSA. But hey, as CBP said to me very recently, "[I'm] not a real American."

Strange. I travel on Canadian and American passports and I've never had a problem. Of course I always use my US passport when coming into the US. In fact, I believe I'm obligated to do so as a US citizen and resident.
Anyway - telling them to "sod off" is a great way to get extra scrutiny. It's just way easier to smile and answer the questions.