HOLY COW! How can this many people be COMPLETELY WRONG!
1. Grounding has nothing to do with lightning. If you think for even a second, that a number 10 wire is going to do ANYTHING productive to halt over a BILLION VOLTS, then you're a complete moron.
2. The NEC, in 2011, SPECIFICALLY says that if the coax is already grounded, NO FURTHER PROTECTIVE DEVICES ARE NECESSARY. Furthermore, since that is always TOTALLY IGNORED, over in the 'should I ground it' section, later, in the 'how can I ground it section' there is an exception written that expands on what "already grounded" means, stating that the internal bonding of the shielding to the chassis/grounding conductor in the receiver is sufficient when plugged into a grounded receptacle. Everyone ignores that one too. DirecTV is the only one that seemed to notice. Their solution was to remove the ground prong altogether, and make the tech ground every system. This decision was due to the fact that 98% of installs would be grounded, but 2% would have a problem or old wiring, and knowing the techs are worthless and wouldn't ground that 2%, they fixed it by saying, OK Ground them ALL.
This is why messenger wire EVEN EXISTS! It was back in the old days when you had a receiver with a ground plug, you grounded the dish, through the messenger, to the ground lug on the rear of the receiver. Then idiots took over and now the NEC is desperately trying to fix it, but no one's listening. Well, it's not that no one's listening, it's more like no one wants to be the one to tell Charlie, "Hey, you know all that grounding stuff I said was gospel and made you spend hundreds of millions on all these years? Yea, well..." Can we say, "terminated with no severence"... lol
If you ground the coax to the ground rod on the home, YOU ARE CREATING ANOTHER PATH TO GROUND WITH A DIFFERENT POTENTIAL. The code doesn't say another GROUND is bad, it says another PATH to ground is bad. If something happen to the ground on a given circuit which the receiver is plugged into, and there is a neutral fault, the receiver passes the ground fault voltage to ground via the shield. Since the shield is no where near able to handle that, it can start a fire. To the person who said there's no way for neutral voltage to get on the coax, you're an idiot, and it's idiots like you, who have never been in the field, but think you know something that you don't, are why we are in this mess to start with. Just the other day I got a pretty decent tingle by a dish mast. I had not hooked up the ground from the block to the rod yet. I got a multimeter, and I had 65 volts AC between the block and the rod. You may say me getting shocked justifies the grounding, but I argue that the customer DID HAVE, and now HAS REPAIRED a faulty ground connection at the ground lug of the home. Had I hooked up the ground wire, and not been lightly shocked, the customer would still be living there with his two autistic kids, with more than 1/4 of the power in his house leaking out as stray voltage to pop up wherever and kill one of them. Or it would have gotten worse, and simply turning on the microwave while he washed clothes causing the dryer and water heater to be on also, could overload the shielding's current carrying ability and melt. It is also not the satellite manufacturer's job to reground your whole house in case of a fault. Their job is to make sure that, assuming the house wiring is in order according to code, that their device is safe. The ground prong DOES THAT.
The bottom line is, by grounding the system, when it's already connected to the house grounding system, you are creating a secondary path to ground, with a different potential, and IT IS DANGEROUS. It cannot hold the voltage from the home if it's asked to, it further masks REAL electrical problems in the home that need to be addressed, and it's AGAINST NEC CODE.