What: Property setters that clone thier input will cause an closed loop event storm with BindTo. Why: The implementation of BindTo tries to be clever and detect that the object tree of the target has mutated and then reapply the binding. However if the leaf property is never unique in a reference sense then the closed event loop doesn't terminate. HowToFix: Only listen for changes to the object structure in the parent of the leaf property not the property itself.
Silverlight can't serialize private members