The vast majority of these International Out of Area calls are from India with someone trying to sell something, a "survey" or a scam usually PC related. I don't think that the phone companies can do anything to stop them. I had a call yesterday from one these computer scam companies informing me that someone was accessing my wife's computer. Which was impossible as it wasn't even powered on.
LG G6 review: Hands-on with LG’s bold, big-screen shot at perfection