Every property interceptor action has a key that can either be specified via an optional attribute property or dynamically when the action is first created. If no key is defined, the system will automatically create one. This key will be used to identify an action for removal. The PropertyInterceptorManager.RemoveAction(interceptorAction) attempts to find an interceptor that matches the one passed in. This match requires that the TargetType, TargetName, Mode , and Key be the same between the two interceptor actions.