"Thats nice. You still haven't given a good reason NOT to mine the border."
Good God, man!
You don't seriously think that we should blow the feet and legs off of men, women and children sneaking across the border to try and get a better lives for themselves, do you?
Here's a good reason NOT to mine the border: to do so would be evil.
"You don't seriously think that we should blow the feet and legs off of men, women and children sneaking across the border to try and get a better lives for themselves, do you? "
Think of it as a deterrent.
If no one crosses, then no one will get blown up.