You need a source, we got em.  https://en.wikipedia.org/wiki/Stop_and_identify_statutes
This isn't silly, it is the basic law of our country.  If the sheriff is asking people for ID without cause he is violating that basic law and as someone who is responsible for upholding the law it's his job to know it.
Even in states with stop and identify statues they can't compel you to produce ID unless there is reasonable suspicion that a crime has been committed, is being committed or will be committed.  This falls under the Fourth Amendment protections against unreasonable searches and seizures.  The police, secret or otherwise, can't ask you to show your papers without good cause.