A judge has sentenced a 33-year-old man to 18 weeks in prison for sending menacing messages to a lawmaker who had supported a campaign to place author Jane Austen on a British banknote.

District Judge Elizabeth Roscoe found Peter Nunn of Bristol guilty of sending indecent, obscene or menacing messages for retweeting Twitter posts that threatened rape and murder.

The case grew out of the successful Austen campaign. The campaign prompted abuse on Twitter from trolls — online bullies who send abusive messages.

Lawmaker Stella Creasy was targeted for supporting the campaign championed by feminist Caroline Criado-Perez, who also was targeted by trolls. Creasy says Monday's sentence of Nunn is a "step forward in recognizing the distress and fear online harassment can cause."