How important is is to cover your door peep house at home or especially when traveling at hotels?

Is the risk big enough that one should cover the peep hole? Can thieves and robbers see into the house by reversing the lens? And is covering the hole with a hanging jacket or other item (sticky note etc) enough to prevent nefarious people looking into the home/hotel? I live in a town where when students go on breaks, thieves break into dozens of apartments in complexes and steal as much as they can

Edit: spelling and grammar

big can door etc home hotels house important lens privacy reversing risk thieves