TULSA, Okla. — It's the illegal immigration you don't often hear about.
These are the immigrants who start off legal, by entering the U.S. on a travel visa.
But then they overstay that visa.
And for fiscal year 2016, the biggest violators, by far, were Canadians.
Quartz.com reports that for just the second time, the government has counted them up.
There were around 120,000 Canadians who overstayed visas, compared to just 47,000 Mexicans.
Quartz says the data shows just how little we know about who's coming and going across the borders.
They say Homeland Security is starting to use biometric technology to track travelers, but the funding is much less than what's being proposed for the Mexican border wall.
You can read more about the story here.