Sad that it has come to this but signage has now been created to prevent those whose experience with books is severely limited from making serious, life- or book threatening gaffes when in their presence.
The signs are appropriate for libraries, book stores, reading rooms, or general household use, and delightfully capture the current, confused book zeitgeist.
It is unlikely that ebooks will ever require warning signs beyond a Magritte-ish This Is Not a Book poster. Kindles, however, may need an additional caveat, the Do Not Taunt This Book alert with image of Jeff Bezos wagging his finger at us.