11.   Feinstein contends that greater control of the porous border between the United States and Mexico is the key to winning the battle over illegal immigration.

12.   However, fresh evidence shows that rebels pass back and forth across the porous border just as Russian forces have undertaken secretive incursions into Georgian territory itself.

13.   It had started in the bottom of a canyon, away from any roads, but close to a faint foot trail for immigrant movement across the porous border.

14.   It suggests a problem of not simply porous borders but a lack of coordination among law-enforcement and intelligence officials.

15.   More and more, chaos in Afghanistan is seeping through its porous borders.

16.   Mexico has a porous border that raises concerns.

17.   Nationality is an increasingly anachronistic distinction in a sports world in which more porous borders have blurred identities.

18.   New trade regulations began opening the already porous border even more.

19.   One key issue, he said, will be how to deal with the incredibly porous U.S. borders.

20.   Pakistan also fears that an attack could produce a humanitarian disaster and send millions of impoverished Afghans fleeing across their porous border.