You've got to hand it to Tom Cruise. He does intensity very well. "If you're a scientologist" he says, wearing a black polo neck with the thumping rhythm of the Mission Impossible theme tune as a background soundtrack, "you see things the way they are".
The clip of Cruise speaking about being a Scientologist, shown at a conference in 2004, has been pinging around the internet after it was leaked last week. In response, the Church of Scientology released a fusillade of lawyers' letters alleging breach of copyright to try to stop it spreading.
The Church is a powerful and litigious organisation, having featured in more than 40 major cases around the world, including in the UK.
Scientology was first considered in a British case in 1968. Two American men, Andrew Schmidt and Joseph Murranti, had come to spend time at the Hubbard College of Scientology in East Grinstead in Sussex. The college was owned by the Church of Scientology, described in the law report simply as "an American corporation". The men's permits to be in the country expired. They applied for extensions.
In July, 1968, following a governmental review, the Minister of Health told Parliament that the organisation "alienates members of families from each other" and had "authoritarian principles and practices" that were a "potential menace to the personality and well being of those so deluded as to become its followers".
The Home Secretary then declined to give the students their extensions saying that in the interests of the British public it wasn't desirable that foreigners should be able to register as students of the corporation because it was socially harmful.
Schmidt and Murranti challenged the Home Secretary's ruling, arguing that he wasn't allowed to exclude them merely on the basis of a judgment that scientology was an undesirable cult. The case went to the Court of Appeal, where the Home Secretary's decision was endorsed. Lord Denning said the consideration of the public good was a legitimate element in the Home Secretary's decision-making.
Another court case arising in Britain was that of Yvonne Van Duyn. She was a Dutch woman who had been refused leave to enter the UK in 1973 to get a job with the scientologists at East Grinstead. She was turned away at Gatwick airport.
The UK objected on the grounds that scientology was socially undesirable. Her legal action was based on a law guaranteeing freedom of movement for European workers. But the British government argued that it was allowed to put limits on freedom of movement, even to people who were not breaking a specific law, if they were involved in activities deemed by a government to be dangerous or harmful.
The matter was referred to the European Court of Justice and it ruled that limits like the one imposed by the British government were lawful.
The Church of Scientology is referred to as a "cult" in some 1970s English law reports but is now a perfectly lawful organisation. Views are expressed strongly on both sides as to whether it is harmful. Scientologists point to their legality, the free choice of adults who join, their promotion of altruism, and their record on helping people with criminal records.
Their opponents say they use badgering techniques and doubt the legitimacy of their beliefs. Those were devised entirely, it appears, by L. Ron Hubbard, a science fiction writer before he formed the doctrines of his organisation. The beliefs charted on the Church's website are mostly quite open ended, saying such things as "scientology is the study and handling of the spirit in relationship to itself, others and all of life".
But it is important to note that nowhere in any of the legal cases have the beliefs of the organisation been evaluated. The question for law wasn't whether the scientologist belief system is better or worse than those of Christianity, Judaism, Islam, or Atheism. Government ministers and law courts can't make decisions like that.
The courts have noted simply that when a Government minister made decisions on entry permits he was allowed to take public policy into account. As long as he did that, his decision could be said to have a "lawful purpose".
One institution unable to provide an independent opinion on the subject is the not-for-profit Cult Awareness Network. Described in scientology literature as "the serpent of hatred, intolerance, violence and death", it used to give advice in America about a number of sects and organisations. It went bankrupt after much litigation. Its name, telephone number and contact details were then purchased by a scientologist.
Professor Gary Slapper is Director of the Centre for Law at The Open University.