These docks are expensive to develop, dredge, manage.
The docks belong to the port authorities. For example, the port authority I am most familiar with, Maryland, owns Dundalk and Sea Girt but P&O has the contract to operate.
Similarly, in New Orleans, P&O has the contract for the Napoleon Avenue Wharf, which is chicken feed in comparison to the entire area.
But -- nevertheless -- it doesn't take much area for contraband to come in.