Get off the sidewalk. No matter what good you think you are doing, you are wrong. This only encourages people to ignore bicycles because they think "see bikes should be on the sidewalk".
Further, more injuries occur to cyclists on sidewalks than on roads. The sidewalk is narrow, so you have less escape route. Cars do not expect you on the sidewalk, so exit parking lots and driveways into you. Pedestrians, kids playing, and other hazards also appear without warning. Sidewalks are usually poorly maintained providing even more hazards.
Further, more injuries occur to cyclists on sidewalks than on roads. The sidewalk is narrow, so you have less escape route. Cars do not expect you on the sidewalk, so exit parking lots and driveways into you. Pedestrians, kids playing, and other hazards also appear without warning. Sidewalks are usually poorly maintained providing even more hazards.