Writing with an active voice is shorter and more direct. You should place the subject before the object — “man eats dog” — rather than the object of the sentence before the subject — “dog eaten by man.”
Examples of headlines in the passive voice
Examples of the same headlines in the active voice
In some circumstances, passive headlines may be appropriate where the reader will immediately identify with the object and be engaged, such as, for example, “President Kennedy assassinated in Dallas.” This is called an instant-identification lead.