I am opposed because it moves the burden of policing software licence compliance to businesses who may have little or no control over their overseas suppliers and who are not in the business of law enforcement.
It doesn't affect me personally. I live in New Zealand. In addition to my full time job (linesman for the local phone company) I also have a small organic market garden. Our accounts are done in OpenOffice running on Linux, so no compliance issues for us. In any case, we supply local supermarkets and do not export to the USA.