Preheat oven to 400°F (200°C).
Pierce the potatoes with a fork and bake for 1 hour, or until tender.
Cut a slice off the top of each potato and scoop out the insides into a bowl, leaving a thin shell.
Add the sour cream, milk, butter, salt, and pepper to the potato insides and mash until smooth.
Stir in the shrimp, bacon, and half of the cheese.
Spoon the mixture back into the potato shells.
Sprinkle with the remaining cheese and bake for an additional 15-20 minutes, or until the cheese is melted and bubbly.
Garnish with green onions before serving.