Robinson, 43, whose real name is Stephen Yaxley-Lennon, is charged with two counts of harassment causing fear of violence to MailOnline reporters Andrew Young and Jacob Dirnhuber through his X account between August 5 and 7 2024.
Opening the case at Southwark Crown Court on Monday, prosecutor Ben Holt told jurors the defendant "threatened" the journalists after what he perceived to be "an unnecessary intrusion into his holiday".
Holt said Young was given a close protection officer by the Daily Mail after photographs of his wife and children were posted on Robinson's X account.
Dirnhuber had to move house because of the alleged harassment, and Daily Mail correspondent George Odling also felt the need to leave his family home after becoming concerned with the publicity surrounding his colleagues.
Editor-in-chief of the newspaper Ted Verity also provided evidence to police of a voicemail he received from an individual who identified himself as "Tommy Robinson" who allegedly told him: "I've already located every f***ing one of you."
The jury panel were told to "put aside" any views they might have about the anti-immigration activist as they were sworn in.
The court heard Robinson had left the United Kingdom for Cyprus the day before three children were murdered in Southport in July 2024.
Holt said he made a number of social media posts following the attack as unrest unfolded across the country.
Jurors heard investigative journalist Young was sent to Cyprus with a photographer to cover the story about "where Mr Lennon was and what he was doing".
"An article was published about him and his whereabouts, both in print and online," Holt said.
Detailing what the prosecution say Robinson's reaction was, Holt said: "What he did, we say, was to intimidate those journalists.
"He chose to frighten them, arrange for individuals to go to their addresses.
"On social media, to millions of followers, he circulated images of their homes.
"His supporters got involved, threatening the journalists.
"Understandably, you might agree, they were scared, in some circumstances, being forced to leave their homes."
The court heard Robinson made a series of posts on his X account responding to the articles that had been published by the Daily Mail and MailOnline.
Holt said Robinson's case is that his family had been put in danger by the actions of the Daily Mail.
He told jurors: "A phrase we will hear a few times in this case, 'what is good for the goose is good for the gander'.
"He acted as he did to protect his family, as such, he says his conduct was reasonable."
Addressing what the prosecution's case is, Holt said: "The prosecution say this defendant - using bully-boy, intimidatory tactics - threatened the journalists.
"He sent photographers to their home addresses.
"He put pictures, albeit redacted, of them out on his timeline on X for the enjoyment and appreciation of his followers."
The trial, expected to last five days, continues.
14°C