The porters are employed by the port itself and not any particuliar cruiseline. They work for tips. We normally tip a dollar a bag. Some can be aggriessive and you do not need to tolerate them. If they get nasty simply tell them to go away and place your bags in the bin yourself but watch and make sure they don't mess with them afterwards either. We did once have a porter in Tampa start screaming at my elderly Mother demanding that he take all the luggage and that we not carry anything onboard. I had to come back down the escalator to rescue my wife and Mom from this individual. He no longer works there and was fired for what amounted to assault on my mom and wife. Usually we have had no problems with the porters when we arrive even though all they do is take your bags from the car and place them in the luggage bin. The ones that often get nasty are the ones grabbing and yelling when you return. We ignore them and handle our own bags to our vehicle.