Using IPAD 3rd Gen 4G ATT. Can you swap out Sim card and use local sim outside US?

[HendoHen]

A friend indicates you can swap out sim card with Verizon iPad 3rd Gen 4G in places like Mexico,Carribean, and Dominican and incur lower cost local data charges but AT&T 3rd Gen 4G models are somehow locked and will not allow you to use local sim cards when traveling outside U.S.

Anybody know?