In the annals of cryptozoology there are many stories of human encounters with creatures thought to be long extinct. One of these that we know from the fossil record to have existed at one time is the Thunderbird.
The thing about seeing something in the sky, be it a UFO or a living creature, there is very little frame of reference for how large an object might be unless you already know or believe you know. Among the best known sightings of Thunderbirds is from Lawndale Illinois, 1977:
The Lawndale, Illinois Incident
One of the most frightening and best documented encounters with giant birds occurred in 1977 in Lawndale, a small town in Logan County. On the evening of July 25, two giant birds appeared above Lawndale. The birds were reported several times as they circled and swooped in the sky. Finally, they headed straight down and reportedly attacked three boys who were playing in the backyard of Ruth and Jake Lowe. One of the birds grasped the shirt of ten-year-old Marlon Lowe, snagging its talons into the cloth. The boy tried in vain to fight the bird off then cried loudly for help.
The boy’s cries brought Marlon’s mother running outside. She later reported that she had seen the bird actually lift the boy from the ground and into the air. She screamed loudly and the bird released the child. It had carried him, at a height of about three feet, for a distance of about 35 feet. She was sure that if she had not come outside, the bird had been capable of carrying the boy away. She later stated that the bird had been bending down, trying to peck at the boy as it carried him off. Luckily, although scratched and badly frightened, Marlon was not seriously injured.
Four other adults appeared on the scene within seconds of the attack. They described the birds as being black in color, with bands of white around their necks. They had long, curved beaks and a wingspan of at least 10 feet. The two birds were last seen flying toward some trees near Kickapoo Creek.
Would a large raptor attack a child? Why not, they look kind of tasty. I friend of mine once told me he witnessed a bald eagle dive on a newborn calf, veering away only as it got close enough to see that there was no good result to come of trying to snatch away something too big to fly with. He had no reason to lie.
Now there is this video going Viral on the web and making the rounds of Unexplained news sites.
This video is an exceptionally well done hoax
According to Live Science
Creators of ‘Golden Eagle Snatches Kid’ Video Admit Hoax
by Jeremy Hsu, TechNewsDaily Senior Writer
Date: 19 December 2012 Time: 06:19 PM ET
A viral video showing a golden eagle attempting to carry off a young child has been revealed as a hoax by its creators.
Students confessed to creating the video as part of a simulation workshop class at the Centre NAD in Montreal, Canada. They used 3D animation to create the depiction of an eagle swooping down and momentarily struggling to carry off the child in its talons, so that they could overlay the 3D elements on top of real video footage of a park.
Well done, but still a fake.