A relative of mine is going on a trip to Africa. They have mobile phone service with a US regional carrier that charges $2.99/min to roam where they are going and doesn't even list roaming data prices. I've offered to loan them my TelnaMobile phone to take on the trip. They are convinced that they will be able to use
Viber to make free calls because it works for them in the USA.
This is the type of person who is very hard to convince of something once their mind is made up. I see a train wreck coming and there's very little I can do to prevent it.