Also the US is a much larger target, it's 300 million people that are almost guaranteed to speak English. Targeting countries like Denmark, The Netherlands or other countries where you'd basically need hire native speaker it's financially viable (That's not to say that the problem doesn't exist in these countries, just at a much smaller scale).
Sounds like the problem is to do with not honoring the do not call list and no punishment for those who don't honor it. Here companies are fined if they call people who are on the list.
