Joking aside, our methods of recording information are hellishly vulnerable. This comes with the density of record. A clay tablet from Mesopotamia does not carry more than 2 kB of info, but 4000 years have gone by and it is still readable.
But, the danger is really high that they will be all thrown out alongside of the yellowed Harry Potter books.
Bit of a tangent: just occurred to me that part of the story arc for the show 'Mr. Robot' is hackers trying to erase an entire knowledge base - the debt history of billions of people. The protagonists try to achieve this goal by peaceful means, but...okay I'm going to stop spoiling it's an awesome show check it out.