This is correct. There were attempts to cross over from Canada, like the Millennium plot, but they were stopped despite a notoriously porous border [0]. [0]: h

This is correct. There were attempts to cross over from Canada, like the Millennium plot, but they were stopped despite a notoriously porous border [0]. [0]: https://en.wikipedia.org/wiki/2000_millennium_attack_plots#LAX_bombing_plot https://en.wikipedia.org/wiki/2000_millennium_attack_plots#L...