Place the bread, garlic, oregano, and parsley in a food processor and process until everything is finely chopped. Add the vinegar and olive oil and process again until smooth. Transfer the mixture to a large mixing bowl.
Place the peppers, red onion, cucumbers, tomatoes, and olives separately in the food processor and process until very coarsely chopped. Add to the mixing bowl. Add the tomato juice, salt, and pepper and stir well. Taste for seasoning, cover with plastic wrap, and refrigerate for at least 3 hours. Fold in the feta and serve cold.