They're annoying birds! They lull you into a false sense of security by singing or pecking the ground for food and then BAM! They're swooping you and clacking their beak and doing repeated dive bombs.
And they've started earlier this year due to the warm end of winter, so some experts were predicting the magpies would be laying twice rather than just once. So rather than 2 months of hell it'll be 4 months!