What I really hate are the airports that try to charge you $10 or more an hour to use their Wi-Fi system.
The most amusing case of this is Charles De Gaul airport in Paris. Where, if you use their general Wi-Fi system they charge you 9 euros an hour.
But, if you go to the Burger King and order anything at all (even a small soda) they will give you a code that lets you use the system for free.