A few misconceptions about the tipping discussion...
1) Waiters want cash tips so they can have tax free income, which is illegal, obviously. What would you say to a doctor or lawyer who wanted to be paid under the table?
2) It is true that most do not make an hourly wage equivelent to minimum wage, and they do need tips to achieve that pay rate, but any career waiter worth his or her salt will make 2-3 times minimum wage...I was making about $8-$12 an hour waiting tables, 25 years ago. Most professional waiters now are not happy with less than $100 a night.
3) There is nothing unethical about the deductions from tips IF the employee is informed and agrees. If not there are lots of jobs out there for waiters.
4) Waiters tips have been "skimmed" for tipping bussers, service bartenders, hostesses, etc. for years because if the waiters are expected to do that on the "honor system" many will not contribute the appropriate amout to those coworkers.