The men were jailed after a failed bid to seek asylum in the US
Two men have started appeals against the UK's first convictions for inciting racial hatred via a foreign website.
Simon Sheppard, 51, was sentenced to four years and 10 months, and Stephen Whittle, 42, to two years and four months at Leeds Crown Court in July.
Sheppard, from Selby, North Yorks, and Whittle, of Preston, Lancs, controlled US websites featuring racist material.
Sheppard's counsel Adrian Davies told the Appeal Court on Thursday the sites were "entirely lawful" in the US.
He said that there was no evidence that anyone in England and Wales - except for the police officer in the case - had ever seen any of them.
Referring to the jailed UK extremist Muslim cleric Mr Davies said: "Despite this, Mr Sheppard has been sentenced to a longer term of imprisonment than Abu Hamza," he told the court.
"These are matters which, in my submission, ought to attract the closest and most careful scrutiny of the court of the supposed legal basis of these convictions."
During their first trial in 2008, Sheppard and Whittle had skipped bail and fled to California, where they sought asylum claiming they were being persecuted for their right-wing views.
However, they were subsequently but were deported back to the UK.
The investigation began when a complaint about a leaflet called "Tales of the Holohoax" was reported to the police in 2004 after it was pushed through the door of a Blackpool synagogue.
It was traced back to a post office box in Hull registered to Sheppard.
Police later found published material including grotesque images of murdered Jews alongside cartoons and articles ridiculing ethnic groups.
The pair were charged under the Public Order Act with publishing racially inflammatory material, distributing racially inflammatory material and possessing racially inflammatory material with a view to distribution.
'Abusive and insulting'
Sheppard, of Brook Street, Selby, was found guilty of 16 offences and Whittle, of Avenham Lane, Preston, was found guilty of five.
Sentencing, Judge Rodney Grant said that he had rarely seen material which was so abusive and insulting.
At the Court of Appeal on Thursday, Mr Davies said that the Act did not contemplate a situation where publication was in an electronic form but only in "hard copy" form.
And publication did not result merely when a website was set up but only when someone actually looked at it.
The hearing continues.