The case of a plumber standing trial for harassment after he tweeted and blogged claims about his wife's alleged affair could help define the limits of free expression online, lawyers claim.
Ian Puddick, 41, set up a series of websites to vent his anger over his wife's alleged seven-year relationship with her boss at a reinsurance advice firm.
Speaking before the start of the trial outside City of Westminster Magistrates' Court, Puddick said the case involved "an appalling abuse of power".
"It is a very, very interesting story. I wish it was happening to somebody else and not me," he said.
"But there are obviously big legal implications for the press and for the public. I've stood my ground."
Puddick, a plumber from east London, is accused of forcing the unidentified director to resign from his post as a result of his claims about the alleged affair.
The court heart that Puddick blogged and posted videos online in a campaign of harassment which left "most of the country" aware of his wife's 10-year relationship with the man.
Lawyers have suggested that the three-day hearing could help define the limits of free expression online.
Puddick claimed police spent £1m investigating allegations against him, and the court heard how counter-terrorism officers helped with the investigation after the incident was reported to police.
Puddick's legal team, led by Michael Wolkind QC, will examine the actions of City of London Police, which sent a serious crime unit to raid his home and office in search of evidence.
The prosecution claimed the plumber's actions forced the director to leave his position due to stress.
The case is being followed by legal and media experts as the battle to regulate what is disseminated through websites and on Twitter is waged in the courts.
Recent cases involving injunctions have also raised questions over freedom of speech and the regulation of the internet.