Brendan Eich's recent resignation as the CEO of technology company Mozilla, best known for the Firefox web browser, is fuelling a debate on the freedom of speech.

Although Mr Eich wasn't fired, it is clear that he was forced out due to his support for the traditional Christian view of marriage and protests from gay lobbyists.

Mr Eich, who co-founded Mozilla and was the creator of the JavaScript scripting language, lost his job because six years ago he donated $1,000 to a campaign that sought to uphold the biblical definition of marriage.

This development has led many to ask profound and worrying questions about the nature of free speech and freedom of belief.

Just how free is our speech if we can be fired simply for expressing a view or supporting a cause on our own time? Reactions have been wide and varied.

The American Freedom Law Centre regards this case as a serious concern. Robert J Muise, an expert in Constitutional law, said: "While a private employer is not a 'state actor' subject to the First Amendment, this case does have free speech implications in the broader sense."

Mr Muise believes that this decision "will chill a private person from publicly expressing his or her opinions on controversial issues such as so-called homosexual marriages, which will then undermine our profound national commitment that debate on public issues should be uninhibited, robust, and wide open".

"This case sends a strong message to those individuals who hold certain religious convictions that they better not convey or express those convictions publicly.

"This sort of bullying tactic is adversely affecting free speech and the free exercise of religion."

But on the other side of the Atlantic, Peter Tatchell, director of the Peter Tatchell Foundation, a human rights charity with homophobia and transphobia at the top of its list of concerns, takes a very different view.

Arguing that the position of CEO is distinctive, Mr Tatchell said: "I defend Brendan's right to free speech but not his appointment and tenure as CEO of Mozilla. His opposition to same-sex marriage is incompatible with the company's very public policy of inclusion and non-discrimination. A chief executive is duty-bound to reflect Mozilla's equality values and ethos.

"Mr Eich financially supported a campaign for legal discrimination against gay couples, in his name and that of Mozilla. He did more than express a viewpoint. He actively opposed equal rights.

"If he had opposed equal treatment for women, black or Jewish people, I'm sure very few people would think it right for him to remain as CEO. I don't see why his support for anti-gay discrimination should be treated any differently."

Mr Tatchell insisted that his support for the rights of the campaigners to put pressure on Mozilla to remove Mr Eich was not based on the nature of their campaign.

Claiming he would support the rights of a hypothetical anti-same sex marriage campaign, Mr Tatchell said: "Supporting equality is a moral good, whereas supporting discrimination is not. I would defend the right of opponents of same-sex marriage to campaign to remove a pro-gay marriage CEO but I would campaign against them and would not want them to succeed."

But not all of those campaigning for homosexual rights are as delighted as Mr Tatchell.

Prominent Anglo-American author, blogger and openly gay Catholic journalist Andrew Sullivan said about Mr Eich's resignation: "The whole episode disgusts me – as it should disgust anyone interested in a tolerant and diverse society."

Speaking out on his popular website, The Dish, Mr Sullivan described the campaign to remove Mr Eich as "unbelievably stupid for the gay rights movement".

He continued: "There is only one permissible opinion at Mozilla, and all dissidents must be purged! Yep, that's left-liberal tolerance in a nutshell.

"He still has his full First Amendment rights. But what we're talking about is the obvious and ugly intolerance of parts of the gay movement, who have reacted to years of being subjected to social obloquy by returning the favour."

Questioning whether he wants to align himself with a cause that uses these kinds of tactics, Mr Sullivan said: "If this is the gay rights movement today – hounding our opponents with a fanaticism more like the religious right than anyone else – then count me out.

"If we are about intimidating the free speech of others, we are no better than the anti-gay bullies who came before us."

He compared the situation of Mr Eich to the one experienced by followers of many religious traditions in medieval and early modern Europe: "It turns out that Eich might have saved his job had he recanted, like all heretics must. But given the choice of recanting, he failed. Hence the lighting of the fires."

A similar view was expressed from London by Jack Hart, communications director of The Freedom Association. The think tank describes itself as "a non-partisan, libertarian pressure group dedicated to fighting for individual liberty and freedom of expression".

Mr Hart said: "The resignation of Brendan Eich is incredibly concerning, because it appears to have come about because of his decision to express his own personal beliefs. It is worrying that people's private and personal beliefs can have such a drastic effect on their employment.

"Everyone should have the freedom to hold their own views and express them in a manner they feel appropriate. In the same vein, people should be equally as free to wholeheartedly disagree. However, such disagreements should not result in someone feeling unable to express their views in public, nor feel able to continue to perform their job.

"If people are to feel their employment may be threatened because of the beliefs they hold, this can only have a negative effect on individual freedom."

Jamelle Bouie of Slate.com argued that if the resignation of Mr Eich is a cause of concern for freedom of expression, Mr Eich is only the most high profile victim of what is an everyday problem in America.

Mr Bouie noted that under current legislation, workers can be fired for their "political views... sporting the wrong bumper sticker... or for being 'sexually irresistible' to your boss".

He added: "Overall, the large majority of Americans have at-will employment, which means that—outside of protected classes such as race or religion—they can be fired for any reason at all."

Therefore, he argues, if there is a concern about human rights raised by this case, Mr Eich is just one victim among many.

The last word here, however, should go to those who organised the campaign against Mr Eich to begin with.

Rarebit, one of the software companies that began the initial boycott of Firefox following Mr Eich's appointment, said this on their blog: "I want to say how absolutely sad to hear that Brendan Eich stepped down.

"I guess this counts as some kind of 'victory', but it doesn't feel like it."

Rarebit explained that their support of the boycott campaign was out of a desire to change Mr Eich's views on the proposition 8 law, not out of any wish to see him lose his job.

"We were more upset with his current and continued unwillingness to discuss the issue with empathy. We assumed that he would reconsider his thoughts on the impact of the law (not his personal beliefs), issue an apology, and then he'd go on to be a great CEO."

Instead, it resulted in a felling that perhaps represented the dangerous side of the power of the internet to organise collective action – something that Rarebit acknowledge in their post.

"The fact it ever went this far is really disturbing to us."