For those using iOS in the enterprise and worried about data leakage, this sort of thing should give you pause.

This sort of thing is difficult to detect in the AppStore Review process so apps that may appear benign could quite easily use this method to try to steal sensitive information with little risk of detection.

We've been lobbying Apple for a while now to improve the controls around clipboard data; specifically to allow us a policy that prevents prevents personal / unmanaged apps from seeing data that was copied from enterprise / managed apps. It might not solve the personal privacy issues but would significantly reduce this as a risk for corporate data.