Internet trolls who post photoshopped images of people or create derogatory hashtags online could face prosecution under new legal rules.
Social media will be more stringently policed after the Crown Prosecution Service (CPS) issued rules on offences for which online users may face criminal charges.
Inciting people to harass and abuse others online is among the offences included in the guidance published on Monday.
It is hoped the updated information will help police determine whether to press charges against someone for their conduct on social media.
It comes after a report earlier this year found one in four teens suffered abuse online because of their identity.
Creating a hashtag to encourage online harassment or pushing for retweets of a "grossly offensive message" are given as examples of unacceptable online behaviour.
Other examples of outlawed practices include doxxing - publishing details about where a person lives or works, or their bank details online.
Baiting - where someone is branded sexually promiscuous - also features in the guidance, along with posting "disturbing or sinister" photoshopped images of someone online.
Director of Public Prosecutions Alison Saunders said: "Social media can be used to educate, entertain and enlighten, but there are also people who use it to bully, intimidate and harass.
"Ignorance is not a defence and perceived anonymity is not an escape. Those who commit these acts, or encourage others to do the same, can and will be prosecuted."