noisy, attack people without a reason, kill other smaller birds, eat their eggs and nestling and take over their spot. I used to live in a neighbourhood with such a beautiful birds, now Crows took over an all I near in the morning is CRAAW CRAAW
A lot of the time it's because you are getting too close to their nests during nesting season. Just take a different path in spring and let them look after their kids in peace.