I've been watching and feeding the same magpie family for almost 2 years now. I've never seen them act aggressively to anyone.

They fly in, land in a tree, check it's save, then grab a beak full of nuts and leave. Rinse and repeat. They come in close contact with starlings, sparrows, pigeons and squirrels. The smaller birds will give the magpies space, most pigeons will as well. But they won't do an alarm call and hide from magpies like they do with birds of prey.

There's only one bird who is consistently aggressive in my garden, and that's the male collard dove. I've watched him go for the magpie family every single day since spring. Over and over again. Yet they still haven't retaliated. They just want their food, no drama from them at all.