There used to be an app that would scan the ip and mac addresses on the network that were already connected to the internet. You could then change your settings to one of the mac addresses and when they were done you'd get the connection to yourself.

I used to travel a lot for work and just refused to pay for WiFi. This was good in airports and coffeeshops when you still had to pay to connect.

Now it's hardly needed, but I could see how it would be helpful where there's still a cost to connect.