I've heard this a lot about geese and swans. It doesn't match my experience at all. These birds won't just randomly attack you, but they will stand their ground and defend themselves and their families. I've come to believe the people who think these birds are aggressive are either the bully kids who chase ducks and pigeons but were shocked when a goose refused to be bullied, or people with zero empathy or respect and can't understand not to get in another animal's face or at least understand they don't want you to come any closer.