News to me, I live ten minutes from the peace bridge, have owned a cottage in Sherkston Ontario for close to 30 years, and cross the border into Canada at least 100 times a year. I have never been stopped leaving the US, or Canada either, I repete, Never.
It is happening only recently. I live on the busiest northern border crossing. Lots of moslems on both sides. The US side comprises a large urban area.