A loyalist flag protester awarded £3,000 in damages over Facebook comments about his children's religion suffered no breach of his privacy, the Court of Appeal has heard.
A lawyer for the social media giant also claimed a reference to him being a "tout" was merely part of a series of online jokes in poor taste.
Facebook is seeking to overturn a potentially landmark ruling that it was liable for misuse of private information.
Barrister Antony White QC told a panel of three senior judges that if the verdict stands it could leave the company at risk of liability for any post identifying a child's religion.
The man at the centre of the case, referred to only as J20, sued Facebook over a series of offensive comments posted on its pages.
He came under focus for his involvement in demonstrations following a decision in December 2012 to limit the flying of the Union flag at Belfast City Hall.
The court heard he has a conviction for disorderly behaviour over an incident linked to tensions at the time.
In September 2013 one page included a picture of the man standing in front of the flag, naming him and stating: 'Meet Sectarian Parade Organiser'.
Among comments posted was one claiming: "Another loyalist bigot exposed... (he) organises more loyalist parades and protests than you could shake your fleg at, he is as bitter as the day is long."
Another poster alleged: "My daughter had three children to this scum woman-beating snake who can't string two words together, he can only mumble."
The woman further claimed that the plaintiff deleted his children from his Facebook page because they had Catholic names.
A third contributor to the page alleged that J20 doesn't bother with his children, offering the reason "probably because they are Fenians".
A separate Facebook page featured a photo of J20 in outdoor gear holding up a fish towards the camera.
Superimposed on the picture were the words: "That's a tout so it is. Said the fish."
Other photographs prompted further captions, including a reference to the plaintiff's sexuality.
Another posted: "They said I could be anything so I became a lonely jobless flegger. I'm a woman beater and take the odd Diazepam so I do."
His photo appeared again on a third web page, along with a description of him as a "parade organiser, knuckle dragger bigot".
In his legal action against Facebook he sued for harassment and misuse of private information.
In December last year a High Court judge dismissed his harassment claim.
But he held that J20 did have a right to privacy over the religion of his children and awarded £3,000 damages.
As Facebook appealed the ruling, it was confirmed in court that the man's children are now grown up.
Mr White contended that the judge had wrongly identified a misuse of private information.
"That information belongs to the children, not the father," he argued.
The barrister also claimed that an impermissible finding was reached on the reference to J20 being a 'tout'.
"This was one of a run of bad taste jokes," Mr White contended.
"The context gives the lie to any suggestion that it was a serious assertion he was an informer."
However, Ronan Lavery QC, for J20, countered that his client's relationship with his children was private and nobody else's business.
"That aspect of his life wasn't in the public arena," Mr Lavery said.
"Alarm bells should be ringing in the context of Northern Ireland, when somebody makes a comment of this nature about someone's children, in the context of bigotry and sectarianism."
Reserving judgment in the appeal, Lord Chief Justice Sir Declan Morgan pledged to give a decision as soon as possible.
