Is it time to start calling out bad cyclists?

a dude in the Rapha ride around Regents Park started shouting at a car that was doing a bit of a shit overtaking manoeuvre. All the windows were closed and I don't think the people inside even realised, not that anything they had done justified being shouted at.

On a similar note, some tall skinny geezer doing laps last night pulling in front of a car just before a pinch point, much to the dissatisfaction of basically everyone in the chain gang. Never seen so many head shaking in my life!