Copied from Wikipedia about Red-tailed Hawks’ behavior:
http://en.wikipedia.org/wiki/Red-tailed_Hawk

“The Red-tailed Hawk is generally non-aggressive toward people and toward other birds, unless there are nestlings present. Approaching a Red-tailed Hawk with nestlings will result in attack and possible serious injury, so it is best to give the nest a wide berth.”

They live anywhere across North America, hence the discussed problem is interesting to many.

I couldn't find any data about flying wild pigs.......