What is it with these deer?

Like most urban areas, I suppose, we have so many deer that they've become garden pests and traffic hazards. They're also attractive beasties, very picturesque as they take a roadside repast on a lightly-forested median or graze in a neighborhood park. But can anyone explain why it is that, nearly every time I've seen them grazing, they all seem to have their tails toward me? Are they being rude, or do they just think that's their best side? :)