Originally Posted by
Caretaker
Depends where you're touring.
The places I like to tour you could leave your bike and panniers unattended all day and night without a lock.
For other places just use common sense, in view, bring important stuff with you and lock bike to something solid.
+1.
OP: I don't ever think I have been denied a request to bring my bike at least inside the vestibule of a grocery store. In some cases, I have brought it inside stores and left it near the checkout stations. I even had a bartender invite me to bring my bike inside the bar. It's polite to ask first. Small town folk are often very accommodating. If you have Ortlieb panniers I believe they make cables to secure the panniers to the racks.