Add the stale bread to a large bowl and cover with cold water. Let the bread soak for 45 minutes.
Remove the bread from the water and discard the water. With your hands squeeze it dry, removing the excess water, while breaking into big crumbs.
In a serving bowl, add the bread, tomatoes, onion, cucumbers, fresh basil, salt, and pepper and mix well.
Cover with plastic wrap and refrigerate until ready to serve.
Add the vinegar and extra-virgin olive oil when, fork at hand, you are ready to attack your dish, not 1 minute before then!