Assuming for a moment you&#x27;re not a legal nihilist, if you feel &quot;banning cash would make illegal immigration harder&quot; is <i>bad</i>, a more logical solution is to make legal immigration easier.  If you&#x27;re OK with all the other consequences of a regulation -- in this case, making it difficult to avoid paying sales&#x2F;income&#x2F;social security taxes, making it difficult to purchase illegal drugs or weapons, to fund organizations deemed by the government to be &quot;terrorists&quot;, etc etc -- and there&#x27;s only one or two known consequences of the regulation you&#x27;re <i>not</i> OK with, it&#x27;s quite possible in many cases to legislate around the downsides.