apparently it is offensive in the UK (in terms of the legal definition of insulting a religion) to refer to Scientology as a cult.
this is very odd. cult, when referring to a religion, is (in all the dictionaries I referred to) explicitly not insulting - indeed it simply refers to the set of practices that aren't part of the formal church for example.
It is potentially insulting to call something a cult that
is not a religion, since in that context, it has the implication of being outside the mainstream - of course, for some adherents of non-religious cults (e.g. cult followers of rock bands like the grateful dead) this is not an insult at all. Indeed, being recognized as outside the mainstream (e.g. goths, punks, skins, etc) is the entire point.
So if someone is insulted by being called a cult, then they are either confused or not religious. If they are confused, this is not a fault of the person using the term. If they are not religious, then the UK law about insulting does not apply.
If the church of scientology is not a religion, then it has some interesting questions to answer about charitable status and other matters.
I personally have no opinion about this one way or the other. I just found L. Ron Hubbard's pre-Dianetics writings to be marginally worse than EE "Doc" Smith's.
If you want to start a religion, or a cult, get a poet (Arthur C Clark would be great as he has initials, and is poetic, and is also dead, but of course he would never have signed up to anything like a religion, so I guess I will just have to start a cult in his name:)
Update: Apparently, the Crown Prosecution Service realized they were on to a lose-lose scenario with this and have dropped the case against the student - but what a stress on poor person who was only using their right to comment on things in a fair and reasonable way.