A man who runs a Facebook page with tens of thousands of followers has been jailed for 21 months for a seven-month stalking campaign of "psychological warfare" against a woman who had rebuffed his advances.
Paul Nelson, who is responsible for the Spotted Portsmouth community information page, left his victim feeling "intimidated and her skin-crawling" after he hacked her emails and social media accounts to track her movements.
The 46-year-old, of Western Parade, Southsea, Hampshire, pleaded guilty at Portsmouth Crown Court to stalking causing alarm or distress.
Sentencing Nelson, who appeared by videolink from Exeter prison, Judge Gordon Bebb QC told him: "Your stalking was calculated, sophisticated, devious and determined and you showed a degree of expertise in accessing her accounts.
"It was no less than psychological warfare and directly intimidating."
The court was told that Nelson tracked his victim's life by searching her email account, and he even turned up at the time of her appointment to donate blood after reading an email confirmation.
He also learned about her movements by checking email receipts from Uber.
After police seized his computer following his arrest, experts found large amounts of data about the victim including Facebook and Google chat logs he had downloaded.
Nelson, who was made subject to a restraining order, also tagged the victim's name on Instagram to a "macabre" photograph of a knife block in the shape of a person.
He also "loitered" outside her home and shouted at her in the street and created graffiti and stickers in a bid to "trash her name publicly".
Henry Gordon, prosecuting, said Nelson had previously been convicted of harassment in 2014 when he had posted a photograph of a former colleague's penis on his Spotted Portsmouth page with a false allegation that the man had attempted to groom his 14-year-old daughter.
Mr Gordon said Nelson had taken the photograph from the colleague's Facebook page when he had left his computer unattended at work.
Charlotte Hole, defending, said Nelson had become "obsessed" with the female victim and added: "He accepts his behaviour was unacceptable."
She said he had suffered from anxiety and depression and drank to excess and the offence followed the death of his father from cancer and his mother developing dementia.
Nelson's Spotted Portsmouth page has gained nearly 80,000 followers by posting items of local interest.