Internet troll Sean Duffy was jailed for 18 weeks by Reading Magistrates' Court for posting abusive messages to online memorials dedicated to dead children.

The 25-year-old was also banned from using social networking sites for five years after admitting posting images on Facebook and YouTube mocking the deaths of four children, including a 15-year-old who committed suicide by throwing herself under a train.

Duffy, of Reading, posted a video on YouTube mocking the girl with her image on the front of an animated train days after the teenager was found dead on a railway line near her home in Worcestershire.

The alcoholic also posted abuse about the girl on Facebook, where he also added twisted pictures of a 16-year-old car crash victim, mocked a 14-year-old girl who died following an epileptic seizure and created a Facebook mocking a 14-year-old stab victim.

Chairman of the magistrates' bench Paul Warren said: "This case serves to illustrate the harm and damage done by the malicious misuse of social networking sites."

Duffy, who the court heard has Asperger's syndrome, pleaded guilty to two offences under the Malicious Communications Act in relation the 15-year-old girl who committed suicide, and asked for three further offences to be taken into consideration relating to the other teenagers.

Others had joined in the abuse, but only Duffy was tracked down using information from his internet service provider.