Ross said the probe of the seven officers’ postings had lasted months because a review of social media profiles can include scouring years’ worth of messages, and proving that the officers controlled the accounts and that they posted specific messages, some of which can be deleted or hidden. All of that is done while also assessing whether the posts violate the department’s social-media policy, which says in part that employees “are prohibited from using ethnic slurs, profanity, personal insults; material that is harassing, defamatory, fraudulent, or discriminatory.”