What do you do when your business sets off massive protests? This is the PR black hole in which the transportation provider, Uber, finds itself. It does little good to make peace with London cabbies. They have one goal and one only — get rid of the company on city streets. There can be no peaceful coexistence. This is frequently the fate of business disrupters who bring a whole new way of operating to hidebound segments of the marketplace. Uber has to work to see that it isn’t shut out because of regulation then it needs to advance bravely in the face of opposition. It won’t be easy. London cab drivers must pass a stringent exam before they are allowed on City streets. They have to memorize the “knowledge” — every street in the city, which is cut up in myriads of ways. Uber threatens that, especially if anyone suddenly can become a driver for hire with GPS on the dashboard. There are some things PR can’t do, and this is one. Mortal enemies are only conquered through force.