A man burned down part of a school after he became wrongly fixated on the idea it was a "playground for paedophiles."
Philip Day embarked upon a determined Facebook and personal campaign against the school based on his belief, which a court heard had no basis in fact.
Prosecutors said the 56-year-old's belief was "not grounded upon any hard facts, in fact quite the opposite."
He filmed clips outside The University of Chester Academy in Northwich, Cheshire, some under the cover of darkness, alleging that the school was harbouring a “paedophile ring," the Liverpool Echo reports.
Day - described by prosecutors as a "driven man" - even turned up at two open events at the school for prospective pupils and their parents.
At the February 2018 height of his campaign, Day, from Runcorn, climbed up on the roof of the school and lit up to 20 fires, including 17 to the roof, systematically removing tiles and piercing the felt before pouring petrol inside and lighting it.
It caused devastating damage, worth up to around £3m.
Mark Connor, prosecuting, told Chester Crown Court: "(The defendant) has publicly made wild accusations that the school was a 'playground for paedophiles'."
Day had claimed there were a number of victims and abusers at the school, the court was told. Mr Connor added: "His campaign gave him a purpose and the prosecution says that he is a man who enjoys the spotlight."
Just before his six-week trial, Day sacked his legal team and decided to represent himself, using the dock as a stage and platform to further proclaim his inaccurate and potentially damaging claims.
Day was found guilty of arson being reckless as to whether life was endangered, arson and two counts of stalking of staff at the school.
A jury of 10 unanimously returned the verdict after more than a day’s deliberation.
Today, Day, of Brookvale, Runcorn, was sent to prison for 15 years, with a five-year extended licence.
Judge Simon Berkson described him as a man who had operated out of "malice", had shown no remorse for his crimes which amounted to a "warped vendetta" and campaign of harassment.
