For the herb aioli, in a bowl combine the mayonnaise, garlic, lemon juice, capers, basil and scallions. Add salt and pepper to taste. Mix well. Cover and refrigerate until ready to use.
Preheat a grill or a grill pan to medium high. Toss the shrimp with the olive oil and season with salt and pepper. Cook the shrimp on the grill 2 -3 minutes per side or until cooked through and opaque at the center. Remove from the grill.
Cut each ciabatta roll half lengthwise and toast them lightly on the grill or grill pan.
To assemble, spread both sides of the ciabatta bread with some of the herb aioli. Working with the bottom slice of the ciabatta bread, stack 2 lettuce leaves and 3 tomato slices. Season the tomatoes with salt and pepper. Top with shrimp (about 6 pieces) and 2 bacon slices per sandwich. Top with the other half of the bread. Enjoy!