Earlier quoted context omitted.
As I understand, they're acting as an agent of the government, it's a private company. So, the 4th amendment protecting against unreasonable searches _by the government_ does not apply.
No, the Fourth Amendment applies to private actors acting on behalf of the government.
It applies to private actors acting as agents of the government, it doesn't apply to private actors who for private reasons not directed by the government conduct searches and report suspicious results to the government (other property and privacy laws might, though.)