If a specific post was interesting or useful to you, we recommend that you Like that post. It tells the post author, and others, that you found the information valuable. Clicking Like is another way to let others know that you enjoy it without leaving a comment.
Log in to join the conversation and Like this content.
My best guess is that they probably violated a rule, or they were a response to a post that violate the rules, and they got deleted along with that/those post(s).
