I've always thought the service feeds are insulated, but it could certainly break down or crack, and I've heard too many varified stories of folks getting zapped when using ladders or installing antennas to think there isn't a problem.
I think the wires in a service feed are far enough apart so that birds don't usually reach from one wire to the next, but I know that large birds get zapped on high tension systems all the time. It's not wirth the risk with metal ladders tom
