A former BBC Radio presenter launched a relentless nine-year campaign of stalking against ex-colleagues and TV presenter Jeremy Vine, a court has heard.
Ex-Radio Leeds DJ Alex Belfield is on trial accused of targeting eight victims including Radio Leeds presenter Stephanie Hirst and BBC Radio Northampton's Bernie Keith.
Nottingham Crown Court was told that the 42-year-old repeatedly posted or sent mocking and abusive social media messages, videos and emails after he was dropped from his mid- morning show in 2011.
Opening the case, prosecutor John McGuinness QC said Belfield had subjected Channel 5 and BBC Radio 2 presenter Mr Vine to a "constant bombardment" of harassing tweets and YouTube videos in 2020.
Belfield is alleged to have made false claims online about Mr Vine relating to the supposed theft of £1,000, then developed a "dislike, almost hatred" of the TV star after the BBC donated the money to a memorial fund set up to honour a friend of the broadcaster.
Mr McGuinness told the court that Mr Vine had no idea that the BBC had even made a donation and "certainly didn't steal it" and that the lies had affected the TV star's sense of wellbeing and optimism.
The court also heard that Ms Hirst felt Belfield's conduct towards her had been sickening, misogynistic and transphobic.
Mr Keith said the alleged stalking had a devastating effect on him and led to worries about his security.
The alleged offences started in November 2012 after Belfield's one-year BBC Radio Leeds contract was not renewed.
The Crown alleged that after leaving the BBC he became disgruntled by what he perceived to be unfair treatment from his managers.
Mr McGuinness told the court although Belfield did not physically stalk his victims, some were worried he may turn up at their homes.
He said : "The stalking which this case is concerned with is of a different type - and is more akin to internet trolling.
"The alleged victims did not want to be contacted by Alex Belfield, they did not want to see or hear or know what it was that he was saying about them.
"But he went ahead and he did it anyway, relentlessly harassing them, knowing or being aware he was harassing them - to the extent that what he did caused them serious alarm or distress which affected their daily lives for the worse."
The prosecution's case is that his actions "went beyond that which is allowed" - and "became stalking, which is a criminal offence."
When Belfield was interviewed by the police, he told officers he was the subject of a witch hunt, the jury heard.
Mr McGuinness told the court: "Belfield said the BBC had legally trained him but he was a whistle-blower and a thorn in the BBC's side."
The court heard that Belfield, of Mapperley, Nottingham, started his career as a broadcast assistant on local radio and in recent years set up a YouTube channel known as Celebrity Radio.
Belfield, who is representing himself in court, denies eight counts of stalking. The trial, which is expected to last for several weeks, continues.