Interesting, I didn't realize he had been detained so much. It does make one wonder how much detaining "activist" types actually helps anything though.

Also, do we know if he was detained by USCBP or CBSA (i.e. Canadian Customs)? You did mention he was detained as he was leaving the country, and unless they were running a special program that day (which happens every so often), usually the US side doesn't examine people leaving.