Nothing like Boulder's liberal policies backfiring and impacting the people that thought that they could get something for nothing.  That said I don't think the ordinance in question is legal as it taxes something outside it's jurisdiction.  The tax is effectively a banned 'import' tax on items created outside its jurisdiction created when they enter its jurisdiction.  If it were to be legal it would instead have had to be a tax at the point of sale, which would also be illegal based on state law.