One nuanced difference is the intents: CSIS was intended to capture "Foreign signals", it wasnt ever supposed to be used on Canadians. the CSE iirc does. I thi

One nuanced difference is the intents: CSIS was intended to capture "Foreign signals", it wasnt ever supposed to be used on Canadians. the CSE iirc does. I think they're analogous to the NSA and FBI respectively.