I was thinking about the tagline for the Word Nerd's blog - "No pocket protectors here; just don't break the spines on the books."
I have another book-related pet peeve - dog-earred corners and highlighting.
In my mind, both taint the book. It shouts, "Look, someone else found me important! Significant! Worthy of their time! Look at me!"
Let me form my own opinion. I'll judge for myself, thank you very much.
I feel the same way about exclamation points. Just because you think it was important, doesn't me I will find it so.
What's your bookish pet peeve?