Bring 12 cups cold water and 2 tablespoons salt to a boil in a lobster pot or large, wide stockpot.
Pick up each lobster firmly, holding the back of the body behind the claws. Add 2 to 4 lobsters to pot; they should fit snugly, but not be stacked. Cover, and cook for 18 minutes. Remove, and repeat with remaining lobsters. Let cool slightly before cracking and removing meat, about 10 minutes.
Heat butter in a small saucepan over low heat. Cook, skimming solids that rise to surface. Season with salt, then pour into small ramekins or a large dish, leaving behind any solids on the bottom; a clear, golden liquid will be left. Keep butter warm.
Place 1 lobster on a cutting board. Twist tail from joint where it meets the body. Cut tail in half down center, keeping shell halves intact. Pull each tail half from its shell, and cut crosswise into 3/4-inch-thick medallions. Arrange cut pieces in shells. Twist claws from body, and discard body. Separate claws from knuckles. Crack knuckles, and remove meat. Discard knuckle shells. Grasp "thumb" of claw, and bend it back to snap it off. Crack claws, and remove meat. Discard claw shells. Repeat with remaining lobsters.
Arrange lobster pieces on a platter, and serve with butter and lemon.
Live lobsters aren't as daunting to handle as you may think. Pick them up firmly, grabbing them from the back behind the claws, and place them directly into the pot.