From Canoe.ca Travel:
Just beneath the cheery din of slot-machine sirens, the sound of blissed-out tourist traffic and the crash of Niagara Falls, an undercurrent of anxiety is flowing among merchants and attraction operators as they brace for what some fear could be a summer of discontent.
As of June 1, those who make their livelihoods serving visitors on the Canadian side of the border will be contending with strict new rules that require anyone entering the United States to carry a passport – including returning American tourists.
The fear is that incoming U.S. traffic will dwindle and the southern Ontario city’s tourism industry will take a beating as a result.