How are you going to link to individual device on a wireless network that has a single IP?
MAC address?
The IP address gets linked to the mobile number. Suppose the Wi-Fi network assigns you the IP address 192.168.1.5, then you go through the verification process where you enter your mobile number and then enter the OTP that you received on that number, then you download a pirated movie.
To find the person in whose name the download was done, the people suing you will need to give the 5-tuple of the connection and time:
- source IP address (i.e. public IP address of Wi-Fi network)
- source port number
- destination IP address
- destination port number
- layer 4 protocol
- precise date and time
(assuming a high-volume CGNAT network. With low-density implementations just the source IP, source port and time should be enough).
With these details, the Wi-Fi network operator will try to find who sent the packets from the NAT logs. The NAT logs will find a match to 192.168.1.5. The operator will then check portal logs to see which mobile number was using 192.168.1.5 at the date and time in the complaint. This will lead to your mobile number which the operator will then give to the court.
One of the reasons all big public WiFi networks in India use mobile number verification is that they can tell who was using the network at the time when the police or courts asks them to.