[eru]

Well, assume your phone number is public knowledge.

[inigyou]

You can get more than one.

[eru]

Sure. Assume the one that's attached to your payment is public.

[wolvoleo]

You can get prepaid ones that you can top up with cash, in many countries you don't have to register them to your name.

[inigyou]

Threat modelling. France is unlikely to tell USA if two numbers are owned by the same person without a good reason.