I have been using WiFi hotspot in a half of USA and all of them are free Maybe your phone was using your mobile phone operator's internet network instead of using hotspot, that's why you got charged.
In the UK WIFI access is free in McDonalds and is usually provided by theCloud. You need to agree to their terms and conditions when you first login but you don't have to pay.
In France the wifi is usualy free at McDonalds, but some ports (application) are not forwarded such as Voip.
In Portugal the wifi is usualy free at McDonalds.
Re: Does McDonald's charge for wifi usage where you are?
I have found that some public Hospitals are running FREE wifi also ..The John Hunter Hospital in Newcastle N.S.W just to name one. It's great if your laid up for a while, you can use your wifi hotspots to connect for mobile and notebooks.
In germany it is free too. You have to register with a valid mobile number and get free service for an hour (I think,this is due to local German regulation) ...
I have been in France most recently.There it is free too - no registration required, you only need to accept once, that you don't misuse the access (as far as I understood ...)
In Western Canada it is always free and working at MacDonalds. At Tim Horton's it is free but often not working. We also have Shaw WiFi that is free to people to have ShawCable or have them as your service provider… they have LOT of locations and they automatically link your laptop, iPad, or phone to the service without a "permission" screen popping up