Look at the recent case of Simon Singh, a science writer who said homeopathy is junk.
He was sued for libel by the quacks and ran up $200,000 in fees defending himself before the other side withdrew the case.
And since it never went to trial they can of course sue him again and cost him (or anyone else) the same amount next time he writes anything.
The libel laws are to the British legal system the same as the lack of a "loser pays" rule is to the US system: a dangerous quirk that needs to be reformed.
And since it never went to trial they can of course sue him again and cost him (or anyone else) the same amount next time he writes anything.