iOS 8 randomises the MAC address while scanning for WiFi networks
If this becomes the trend (which in my opinon would be nice) it will become a big problem for companies that specialise in customer tracking e.g. for supermarkets and big department stores. Previously it was quite easy to track a customer, how long he or she spends time in the store, which floors he or she visits, etc. by putting up dummy WiFI-networks that the customers phones find by giving out their MAC-addresses.