Facebook copyright issue due to claims of infringement to content

On demands of members of a facebook group to publish a joke's book, i as an admin, made all the efforts to get it published. The contents of the book was mainly derived from the contributors of the group. Soon after it was published, two particular members cum moderators raised about the copyright issue saying that the editor stole contents from the original writer Some points are: > the contents of the book are from the facebook group page. a few number of jokes were created on own and not posted in group. >the group does not have any valid bank account and not a registered society. > the editing and proof reading part was solely done by the editor. > thanksgiving note was mentioned in the prefect > the statement "the book is a collection of unique jokes contributed by the members" is clearly mentioned Sir, i would like to know whether giving copyright to my husband as an editor of the book is legal or not? Please clarify