The mother of murdered toddler James Bulger has been targeted by a troll on Twitter.
Denise Fergus said she could not believe the message which apparently blamed her for her son's death in 1993.
Mrs Fergus wrote on the microblogging site: "Cant believe that some1 on here is still blamin me 4 my sons murder it took me a long time 2 stop blamin myself thanx 4 ruinin my evenin."
The offending tweet appears to have been deleted but the Daily Mirror reported it said: "(Denise) was to blame. She let go of James' hand."
Her husband Stuart told the paper: "It affected Denise. Twitter have got to act against trolls. They face no consequences. It's gutless."
Critics have called for Twitter to take faster and stronger action in the wake of recent abuse on the site.
A number of people have been arrested for posting offensive messages threatening to kill or rape.
Cyberbullying is believed to have led to schoolgirl Hannah Smith killing herself after she endured months of abuse from trolls on the website Ask.fm.
The 14-year-old from Lutterworth, Leicestershire, was founded hanged in her bedroom two weeks ago.
James Bulger was abducted, tortured and killed by Jon Venables and Robert Thompson in Liverpool in February 1993.
Venables and Thompson, who were just 10 at the time, abducted James from the Bootle Strand shopping centre before carrying out the murder which shocked the nation.
The two boys were jailed for life but released on licence with new identities in 2001.