The Moral Minority and the BBC: a reality showdown close to Jerry Springer's heart

The BBC placed a guard on the homes of some senior staff and took legal action to shut down a Christian website that published the addresses and phone numbers of its executives, as the row escalated over last night's broadcast of Jerry Springer - The Opera.

The BBC action followed threats of "physical violence" and even "bloodshed" against staff, including Roly Keating, the head of BBC2, and their families. Personal details had been made available both on the website and in an email distributed by Christian Voice, one of the groups that has led the extraordinary backlash against the corporation for refusing to pull the broadcast. The protesters claimed its content was blasphemous.

The email from Christian Voice's national director, Stephen Green, to subscribers - obtained by The Independent on Sunday - stated: "We make no apologies for giving their home addresses and in as many cases as we can, their phone numbers ... We know normal protests are channelled in such a way as to be ignored."

The strength of the protests had taken the BBC by surprise. Last night, many in the arts and broadcasting feared a rise in aggressive campaigning to curb artistic freedom in Britain.

They point to the controversy over the play Behzti (Dishonour) in Birmingham, which closed after Sikh protests led to violence, and the BBC's decision to pull the comedy series Popetown last year, as evidence of organised lobbying across religions. A government Bill outlawing incitement to religious hatred is also thought to be adding fuel to the campaigns.

The writer Philip Pullman told the IoS: "I do worry that we are entering a time of greater excitability, greater intolerance. We are now expecting people to feel aggrieved and inciting them to do so, and providing them with an excuse by getting plays put off." A screen adaptation of Pullman's trilogy His Dark Materials is among the casualties, with references to God and religion removed.

Last night's broadcast of Jerry Springer - The Opera went ahead despite more than 30,000 complaints, a record number - many as the result of coordinated campaigns. A 250-strong demonstration and prayer vigil took place outside the corporation's TV centre in west London before the programme. On Friday protesters had tried to storm the BBC building.

Christian Voice claims the production ridicules Christianity. "They [the BBC] hold ordinary people and almighty God in utter contempt," said Mr Green, 53, the founder and national director of the group, set up more than a decade ago.

There is no suggestion that Christian Voice's members made calls to the BBC executives, but corporation insiders believe the group must have been aware of the consequences of publishing them.

A BBC spokesman said: "We can confirm that lawyers acting for the BBC requested that the site was removed to prevent the publication of the private addresses and phone numbers of our staff."

Mr Green said he "absolutely" condemned any threats. But he added that protests would continue, possibly outside the homes of BBC staff, and he is threatening legal action for blasphemy.

In Jerry Springer, a parody of the trash-talk-show host's TV series, Jesus is portrayed wearing a nappy and admits to being "a bit gay". The show aroused few murmurs of protest when it opened at the National Theatre in 2003.

The NT's director, Nicholas Hytner, said: "I am assuming that the people who thought they'd be offended didn't buy tickets. I got a surprisingly small postbag. Try as I might I can't see what the fuss is about."

Many complaints to the BBC have been as a result of reports that the opera includes 8,000 swear words, although the true figure is around 290. The higher estimate was a result of multiplying the expletives by the number of people singing them in the chorus.

The religious backlash is worrying many. The comedian Linda Smith, the president of the British Humanist Association, said: "These people seem to have their tails up at the moment. It's partly after seeing the success Sikhs have had in Birmingham and looking to America and the stranglehold that the religious right have on policy there." Joan Bakewell, who chairs the National Campaign for the Arts, said: "We are on the edge of people feeling that if they are offended by something, it should be outlawed. This is damaging because all sorts of things could be offensive."

But a spokeswoman for the Evangelical Alliance said it should have been pulled, arguing that the programme breached BBC guidelines.

The Conservative deputy leader Michael Ancram also criticised the broadcast. Speaking on BBC Radio 4's Any Questions, he said: "You can choose to go to the theatre ... Public service television, I believe, has another duty and that is to exercise a degree of caution which is not there for the theatre to exercise."

Additional reporting by Andrew Johnson and Steve Bloomfield