[sauropod]

Cinder blocks?

That’s not an effective deterrent at all.

[FroggyTheGremlim]

Oh, I think cinder blocks would work just fine with a few well-armed border patrol agents near by.

Shoot one or two of the illegals, and crossings would cease, or at least drop dramatically.

I also kinda like the exploding robot method.

[Cobra64]

Agreed. I think it is a symbolic gesture.