The patenting regime is currently experiencing a significant amount of upheaval, particularly in China and the United States. This makes it harder to predict the prospects of a successful grant. Furthermore, prior to publication, the existence of patent applications is not verifiable using statutory databases, meaning there is always a potentially substantial backlog of competitor activity that is not visible, also, since companies do not always keep these systems fully up-to-date in terms of legal ownership, the information that is visible is not always entirely accurate. Even when granted, in addition to the ‘"normal” uncertainties present in IP rights (summarised in Part 3), the monopolistic rights associated with patents make them particularly susceptible to legal challenge, and defence can be costly.