I still don't understand why taxis need a medallion from the city to operate, but Uber and Lyft drivers don't. The quote from Judge Posner at the end of the article is totally inane, and has to be out of context.
according to the article the medallion allows you to roam the street and look for someone to hail you. Uber and Lyft were ruled by the court to be more like arranged rides (limo service). It likely makes sense if you consider the original purpose of the medallion. I think (need to check again) that it was not to create monopolies but to reduce the danger that ramped up in the early days with unlimited numbers of cabs roaming the streets, zooming and cutting each other off to get a fare. If you call for a ride that public safety concern is gone