[Quick1]

A posted sign at the entrance. By passing that sign and entering onto CC property, you agree to those conditions.

Pretty sure that's false, and anyway, I've never seen a sign at any of the places that have asked to see my receipt.

(You cannot make a contract to do something illegal)

Like an illegal search of my possessions?

The store’s problem is that the arrest (by the store manager) was made off their property.

Many times, parking lots are part of the store's property. I can't say if that's true in this particular case, however.

[Quick1]

Oops, dropped a /i.

[MindBender26]

There is WAY to much incorrect legal advice going on here.

>>>>A posted sign at the entrance. By passing that sign and entering onto CC property, you agree to those conditions.

>>Pretty sure that’s false, and anyway, I’ve never seen a sign at any of the places that have asked to see my receipt.

No it is not false.

>>>>(You cannot make a contract to do something illegal)

>>Like an illegal search of my possessions?

To be illegal, it must violate a LAW. That is not the case here.