All satellite system should be grounded, even with properly grounded the system, but things still happened. I have had replaced a DTV system not long ago cause by lighting hit, not direct, the system seen grounded to the accordingly procedure, but customer still got hit, loss the receiver, VCR and TV, and fire on an extension cord.
So, for bestter protection, beside the system grounded, have the best surge protector connected between the cable in and receiver. Not all surge protector are equal, get the one with warranty and name brands.