In a blender, liquefy the canned tomatoes and pour through a fine mesh strainer and into a large bowl to remove the seeds and skins. Discard solids and set aside the bowl of juice.
In another bowl, toss together the tomatoes, bell pepper, cucumber, onion, garlic, vinegar, and a pinch of salt and pepper. Let stand for 5 minutes until the vegetables begin to release some liquid.
Stir the Sriracha sauce into the tomato juice then add in the vegetables. Cover with plastic wrap and refrigerate for 4 hours and up to 2 days.
Meanwhile, boil a large pot of water and cook the shrimp until they turn pink and curl into a tight circle. Drain and rinse with cold water to stop the cooking. Chill.
To serve: Ladle soup into the serving bowls, top with chilled shrimp and diced avocado and drizzle lightly with olive oil.