Social media is to be more stringently policed under new rules on offences for which online users can face criminal charges.
Internet trolls who create derogatory hashtags or post humiliating photoshopped images could face jail, the country’s most senior prosecutor has warned.
The Crown Prosecution Service has published new guidance to help police determine whether to press charges against someone for their behaviour on social media.
It comes after a major report found one in four teenagers suffered abuse online because of their gender, sexual orientation, race, religion, disability or transgender identity.
Cases of sexting that involve underage children should not be pursued for prosecution if the images are shared consensually between two children of a similar age in a relationship, the CPS said.
But it added that if such cases involved "exploitation, grooming or bullying" it may be appropriate to attempt to prosecute those responsible.
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."
Creating a hashtag to encourage an online harassment campaign, or pushing for retweets of a "grossly offensive message" are given as examples of unacceptable behaviour.
Other examples of outlawed practices set out in the guidance include publishing an individual’s home address or bank details on the internet, dubbed doxxing.
Baiting – when someone is humiliated online by being branded sexually promiscuous – is also mentioned in the guidance, as is posting "disturbing or sinister" photoshopped images of someone on a social media site.
Prosecutors acknowledged, however, that many photoshopped images were humorous and inoffensive".
The CPS also announced the launch of a hate crime consultation, issuing a series of public policy statements centred on combating crimes against disabled people, as well as racial, religious, homophobic and transphobic hate crime.