Is it time to start calling out bad cyclists?

I've seen a few people cruise casually through intersections without a single glance at the lights or head check for cross traffic. It's totally surreal.

The last person I saw to do that I asked if he wanted to get hit by a van. He acted nonchalant. I also warned a guy a boris bike to look before overtaking another cyclist as he went right in front of a car going at speed. He shrugged and carried on his way. If I see him get hit by a car, maybe I'll just shrug and carry on.