Earlier this year, England was struck by a large number of riots in multiple cities across the country. The riots were totally unexpected and stuck the country with horror at the ferocity, and it took the confused administration and police some time to tackle the riots and to bring order back. Post the riots, there was a massive push to strike back with ferocity at the people involved in the rights, with talk of removal of benefits to those who were involved, as well as passing sentences that were at the higher end of the typical sentences for such crimes.
These riots were also fanned by social media, with Twitter and Facebook being used for organizing people and passing on information about possible locations of riots. This usage of social media is also considered as involvement in the crime, so you had the police and investigating agencies getting involved in finding out who said what on Facebook, and using such investigation as a part of the case against them. Consider this case where a person was sentenced to 4 years for such a crime (link to article):
A British court on Wednesday sent a stern warning to thugs using social media to incite riots by sentencing a man to four years in jail after he admitted inciting public disorder on Facebook during riots in England.
Jamie Counsel, 25, set up a page called Bring the Riots to Cardiff, later changed to Bring the Riots to Swansea. The sentence should be a warning that anyone using modern media to incite riots would face stiff punishment, said the judge at Cardiff Crown court.