Yes, egg addling (shaking of the eggs to prevent production of cygnets) is practiced around the world to control the population of many species of birds. Is it cruel, probably not at cruel as having an over abundance of birds and no natural resources to support them with the possibility of starvation, etc. However, many "purist" biologists (those that believe that if it is not native to an area, it must be destroyed to save native species. This practice is being conducted nationally and worldwide not only to the Mute Swan but many other birds that someone does not consider a native species.

Do not move the eggs or the nest. The parents know best and will abandon any eggs that will not produce viable offspring. The Regal Swan