Did you watch on CNN Go? They mentioned and showed how easy to across America border to Canada, not by imagary, I have seen enough in real life, I personally did cross canada without see a custom present. And that News reporter at CNN did same thing, walk into canada, look ma! no US custom. CNN news reporter did ask US custom officials on how secure the border it is, the answer was very vague! He didn't say its 100% secured or not even mentioned how secured it is, they simply said they are working on improving them... what does that means? They won't say not secured enough cuz it is what it is reality.
You have to keep in mind the maximum security prison is ONLY 30 miles away from Canada border, and he was not checked for 7 hours meaning he HAD a good head start. If he was discovered less than 2 hours, hes likely going to be recapture.
My suggest use Google map, look along the border between US and Canada near the prisons, using satellite feature, and you will drop your jaw on how many unfenced borders along, plus you will see road gap, about 20 feet apart, no fence, no nothing but grass where you CAN simply walk across. Look in google map, will ya? I have seen plenty, its so much that government can't cover all of them. Thats right, plenty no mountains, no difficult terrain, just grass plains leveled, etc.
Plus you forgot one thing... I live in Upstate NY, and live near US/Canada border, how can I miss that or how can I have imagery when I actually saw them?, even across ed border without seeing US custom officials?
Problem here I am seeing is that its difficult to monitor remote border line, even with security, they can be confused between human and animals especially during night time. There is no way they can accurately monitoring thousands of miles or KM whatever you call it. Secondly, about 10 years ago, theres been mentioned on TV news with captions of course about Mexico border and drug smuggling, US custom officials never said they were 100% secured, they did admitted only 18% were secured, while 72% isn't and mentioned it is very expensive, congress won't expand the budget to cover unsecured border line. They didn't say where due to security but 72% unsecured border, should be very easy to find which I find it true. Officials even mentioned as why this is very difficult to win drug war, and blocking illegal immigrant is next to impossible.