I spoke to this lady after she took her ‘blurry’ photos. She was very unhappy with her Canon camera and she was talking about switching to Nikon. She was blaming the camera.
The main problem with her Canon camera was how she was holding her camera and her lens.
She was trying to zoom with her left hand by holding the lens from the side. Basically, she was holding the full weight of the camera/lens with her right hand. Of course, her photos would be blurry, the camera was moving too much.
As photographers, we are supposed to be tucking the elbow into the stomach to give it additional support.
Canon camera taking blurry photos
Before (left) and After (right)
Camera: Canon 7D ISO 500 and 1/320
Lens: Canon 70-200mm f/4 @180mm and f/10
Processed with Darktable 2.0.6: http://www.darktable.org/