The objections to approving the sale centered on arguments about who controls U.S. ports, especially after the September 11, 2001 attacks. Some opposed to the sale have argued that no foreign government should be permitted to own such strategic assets while others argue that port security should remain in the hands of American firms under American control at the very least. Few had offered similar objections to the P&O's ownership, until the proposed DPW takeover brought attention to the situation. Over 80 percent of the terminals in the USA are already controlled by foreign owners.