It's not a prank call, more like a scam call.
We have tons of those in Taiwan, and I mean like I get one of those scam calls at least once a day on a daily basis. (Back in Taiwan)
They're mainly from Mainland China, and sometimes they'll call the users to tell them how to operate ATMs in English (In which most Taiwanese did not have knowledge about) and scam them for their money. (There are more types of scams other than this one)
With all the advertisements and warnings from nonprofit groups and government, people are aware of the scams and won't easily fall for such stupidity anymore.
I guess those scammers haven't got the people proficient enough in English to scam you guys in America.