I sometimes give cars a friendly little knock or tap with my hand or knuckle on cars (with people in them) that block bike lanes, crosswalks, and sidewalks. For example, a construction crew sitting in their cars waiting completely blocked a sidewalk which forces biker riders to jump curbs so I gave them a tap just to let them know that people use these lanes and spread the awareness. A Fed ex delivery driver did the same sort of thing while waiting for traffic (I understand this one much more), but he pulled up right as I was coming along. Tap tap. while I was riding away a couple of older gentlemen began yelling at me to come their way as if they were angry about me doing this. I was going along pretty good and didn't bother to see what they had to say but now I wish I did. Anyways I was wondering what you guys thought about bikers doing this. Good idea or bad idea? These are in places where I'd rather not take the lane (I've been run off the road in these areas before).