Less obvious than a wall, but effective nonetheless

rare bird - unless you're hezbollah 

Venezuela citizens can't get passports to leave because, naturally, there's a paper shortage.

In the US, we need a wall to keep people from coming in, while communist governments have always used them (and barbed wire and machine guns and mines) to keep their captives in.

Sad.

Sadder still, Venezuela has found enough materials to provide passports for Middle eastern terrorists, as CNN (of all organizations) recently uncovered.