The usual hacker's argument: if someone doesn't put locks on their windows, it's their fault if they get burgled.

I was using the wi-fi in the Arrivals Lounge only this morning. It was sloooooow. That's not going to get any better with unauthorized users hijacking the system.

I'm not claiming to be a saint myself. I will raise my hands and admit the on the rare occasions my own broadband connection fails, I have been known to use the connection from a local shop which isn't protected. But this behavaiour does have detrimental consquences for others. I don't actually think it should be encouraged on this board.