Is it disrespectful to keep and read an old diary one has found?

[Ulla]

If you find the diary of your child or your partner when clearing up his/her room, it is clear that reading it is a breach of trust. But what if you find the diary of someone who is already dead? Should it be left alone?
Well, Riko in A Whisper of Leaves by Ashley Capes, accidentally finds a leather-bound journal in the forest below Mt. Fuji, and she is determined to read it. An amazing, sometimes creepy story enfolds... It is well worth reading!
I think Riko is right, because the writer of the diary might have wanted it to become known someday. Perhaps even win some fame from it. Anne Frank wanted to become a writer. After her deportation her diary was found in the hiding place and kept by Miep Gies. After Anne's death in Bergen-Belsen her father, who was the only survivor of the family, has made it public. What if he hadn't done so? The Diary of a Young Girl