I've seen two definitions of salmoning. 1) Riding against the flow, and 2) Filtering to the front and "schooling" between the stop line and the crosswalk... or in the crosswalk... or most of the way into the intersection...

I think the second is the more common definition. I will do this occasionally to improve my ability to be seen at intersections, but generally only when the lanes are wide enough that cars can pass me back easily on the other side of the intersection if they need to.

I don't like riding on the sidewalk, but I probably wouldn't call someone out if they seemed to be doing it safely. Are they riding in the lane most of the time, but only jumping up on the sidewalk to pass to the front of the line? I wouldn't like that at all. I think you gotta pick the place you want to be and stay there. Moving frequently between street and sidewalk is asking for trouble.