**Using a public computer**, for example in an Internet café or a library.This computer is regularly used on this local network, and its MAC address is not associated with your identity. In this case, MAC address anonymization can make it impossible to connect. It can even **look suspicious** to the network administrators to see an unknown MAC address being used on that network.
Every network interface — wired or Wi-Fi — has a [[!wikipedia MAC address]], which is a serial number assigned to each interface at the factory by the vendor. MAC addresses are used on the local network to identify the communications of each network interface.