They have region codes but are different from regular DVDs. They use (or can use) regions A,B, and C.
A Americas; East and Southeast Asia.
B Africa, Europe, Oceania; Middle East; French
territories; Greenland.
C Central and South Asia; Mongolia, Russia, and
People's Republic of China.
It's a band-aid at best since you know someone will take the time and energy to rip them and sell them worldwide or make the player region free (as we do now with DVDs)