Sure, I've violated their rights, but they are on my property and they are willing.
Your analogy doesn't wash. They are perfectly within their rights to search bags of people who leave their premises. College libraries used to do this before they had those electronic gizmos, to keep people from exiting with library books.
As I said in my original post response, you have the right to shop someplace else. If you frequent their premises, you've gotta follow their rules.
"They are perfectly within their rights to search bags of people who leave their premises."
The following part of the Fourth Amendment needs to be emphasized:
“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures…”
It’s important that this is a Constitutional protection from Government but for this discussion that importance is secondary to the importance that it is also an authoritative and clear statement that the right exists.
Where is it stated with equal authority (and clarity) that "They" have a right to search bags of people who leave their premises."