Is this a US-centric view? Presumably crossing national borders, as noted in the article, it would be more effective to catch IMSIs. When there are lots of cou

Is this a US-centric view? Presumably crossing national borders, as noted in the article, it would be more effective to catch IMSIs. When there are lots of countries clustered together in a smaller geographical space, ie, not the USA, it might be relevant. But I don't know.