Now, I'm not sure that this particular law isn't a little overboard. Sometimes riding your bike on the sidewalk could be ok for the general public in my opinion. But not in the middle of Center City at Lunch or Rush Hour. And certainly not in such a way that allows YOU, the law-breaker, to yell at ME, the law-abider for getting in your way. Thusly the reason I've been annunciating "Sidewalk!" at you miscreants with an extra emphasis on the "WALK" as you invade my pedestrian territory.
You, the law-breakers, seem to have been unable to comprehend the subtle jab embedded in my admonition when you fly by and between myself and my wife at high speed with your messenger bag smacking people in the head for good measure as you go. I can understand that this may be difficult as your reckless disregard for the law has probably also caused you to land on your unhelmeted head several times after being thrown over your handlebars by an impact with a vehicle who was driving the correct way down a one way street. (Unlike you.) So, I have pasted the finer points of this particular law for you below. Hopefully this will clear everything up.
12-808 Riding on Sidewalks
(1) No person shall ride a bicycle upon a sidewalk within a business district, as such district is defined in The Vehicle Code.
(2) No person 12 years of age or more shall ride a bicycle upon any sidewalk in any district.
(3) Whenever any person is riding a bicycle upon a sidewalk, such person shall yield the right-of-way to any pedestrian and shall give audible signal before overtaking and passing such pedestrian.
(4) In areas under the jurisdiction of the Fairmount Park Commission, riding bicycles on sidewalks and foot paths may be permitted when authorized by regulations of the commission. 10
(5) Notwithstanding the provisions of Section 12-811 of this Chapter, the penalty for violation of this Section shall be a fine of $10, together with the costs of prosecution. 11
(6) An individual employed under delivery person status, whether in food service or courier industries is not in any way exempted from the above restrictions. If qualifying for other "hipster" exemptions within the body of this code, you may apply for a liscence from the Philadelphia Traffic Code Enforcement Department that will allow you to ride your bicycle on posted blocks of the South Philadelphia District provided that you remain there for the rest of your life and don't bother the rest of us.