These are the only three 'areas' (subsets of parc ex, mtl north, stmichel) where I would pay (slight) attention to my surroundings at night in Montreal. They don't look
that bad during the day. But I think with ghettoes looks can often be deceiving. The crappiest parts of Montreal are typically not as dense as the central areas. So there is more greenery and sometime single family homes, which makes them look Ok to the untrained eye. Mind you, I'm not saying these areas are dangerous... just sketchy.
Lacordaire/henri-bourassa
St-michel metro area
Parc ex innards Looks like streetview is from 07'. Maybe it really is bad !
Overall, I'd say the metro system is probably the least safe part of the city, which is saying something because it really isn't bad. The NY subway is 10X more terrifying until you realize how insanely over-policed the whole city is. When I was a teenager there was never, NEVER security of any kind in the metro late at night. It was spooky at times.