Off-topic, but your sentence made me realize a useful difference between "lawful" and "legal". I first read "legal" as "relating to matters of law" rather than "lawful", and then realized you meant the latter. Now I see why the word "lawful" might be used!

Regarding your actual reply, though, that basically means we shouldn't really hold our breaths for this to actually stop calls? :\ Just less fraud, which is nice, but from the only thing that makes these calls such a nuisance.