It is a fact that many women have migrated to the US to escape from perpetrators of domestic violence. However, when perpetrators are persistent there are no boundaries to stop them.
Currently, the United States law on Stalking don't even cover international Stalkers. It covers stalkers who travel from State to state and to US territories and Indian tribes.
Secondly, if the victim obtains a protection order from the country of origin of the perpetrator, that order is not given Full-faith credit in the United States.
A perpetrator can simply obtain a proxy (investigator) and pay to stalk its victim. With the help of transmission of videos and cell phone, he can easily know where his victim is and what she is doing and continue to stalk and threat them.