Luxury watchmakers are apparently starting to add anti-forgery features to make it easier to identify counterfeits (via Division of Labour).
How embarrassing for them to have to admit that the cheap knock-offs are otherwise indistinguishable from the real thing.
As I’ve said before, the legitimate purpose of trademark law is to protect the consumer from inferior goods. A technical or artistic innovation is a positive externality, which copyright and patent law is designed to internalize. A brand established by costly marketing is of no general benefit, and cannot be deserving of state protection except inasmuch as it is a guarantee to the consumer of superior quality.