The big issues would be when worker starts and ends, self direction in terms of how they do the job (and associated liability), worker's comp, unemployment insu

The big issues would be when worker starts and ends, self direction in terms of how they do the job (and associated liability), worker's comp, unemployment insurance, and tools / vehicles (I.e. should Uber be required to pay ~50 cents per mile to it's drivers. W-2 says yes, 1099 says no).