This is funny actually - two locations -
First one was in Wisconsin (cheese of course) and I was an Auditor at the time and as I walked into the reception area of the plant to check-in prior to starting a 3rd party audit a notice was posted in the vestibule area that stated due to safety/security and food defense all visitors briefcases, bags, etc. would be searched prior to entry. There was also an allergen statement on the notice about not bringing food into the facility that could possibly cross-contaminate.
I checked in, signed the visitor log and showed an ID card - nobody searched for anything.
Yet, the search statement was on their food defense and on their allergen documentation that I looked. When I asked why my bag had not been searched I was told "we would never do that to an Auditor."
Second one was in California, this time as a Consultant entering an allergen free facility having to pass thru a blower and airlock system entryway - interesting actually and then then the notice about not bringing allergens into the allergen free facility - that was not pre-entrance, but only posted in production - so you walked straight thru exposed product and then see the sign.
In partnership we operate a store and are installing a sign pre-entrance that states all hats must be removed prior to entry and bags are to be left in a holding area outside of the store - why, because the area that we are in has experienced several robberies that included the bad guys having their guns on top of their heads under the hats and in their bags. It is a policy that we will enforce, at the same time our staff is trained with weapons.
Going back to food defense, we are familiar with a number of food, logistic and packaging companies that we consult with and have audited that have policies in place for searching lockers, people, their bags, etc. and they stick to their policy because we know there has already been incidents of people coming in off the street and proceeding to maim and kill people in a number of different companies including food, logistic and packaging companies.
Most of the companies we work with have policies in place for searching of contractors bags, equipment, chemicals, etc -- this should be a standard practice but alas it is not and we'll continue to hear and see news about places that were robbed, someone was injured or killed or the entire plant had to go into shut-down because an Auditor walked across production with their lunch.
In our own food plant I have no qualms about searching an Auditor's bag, considering the statement about search is on our policy I better search his/her bag.