Picking up on Trevor's point on libel laws in his post below.
Trev writes that "in addition, blogs (and podcasts) are also subject to all the normal rules (eg libel laws), so that ought to be enough".
This is something of which bloggers should be mindful.
While something they write may not be actionable in the country in which they reside (and in which they wrote the post) it can be an entirely different matter in the country where the post is read.
It was a long established legal precedent in common law countries (Australia, the UK, USA, Canada, South Africa, India, Malaysia etc) that an act of defamation (or libel) occurs where the article or broadcast is perceived, NOT necessarily where it is written or published.
In other words, if you write (or post) something about an individual, which under the laws of your country is not defamatory but it is read in a country where it is defamatory, you could be sued.
Looking at it another way, for a person to sue for defamation successfully, they have to establish that they have a reputation that has been damaged. You may post a piece about an individual who does not have a reputation to protect in your country (they have no public profile) but whom is well-known in another country.
If that person can prove several other people in a particular jurisdiction (country or state) read your post (and trackbacks and comments make that easy) and that the post was injurious to his or her reputation, you could be in trouble.
The High Court of Australia considered the issue of defamation and the internet in 2002 and ruled that Melbourne-based mining magnate, Joseph Gutnick, could sue Dow Jones for defamation after the latter ran an article on the subscription Barron's Online web site, run out of the USA.
The court ruled that because Gutnick could establish that people read the Dow Jones article in the Australian state of Victoria (where he resides and has a reputation), he could sue for defamation in the Victorian Supreme Court.
The decision caused near-hysteria among many free-speech advocates, who claimed the court's decision was radical.
It wasn't. It simply re-stated precedented dating back to the mid 19th century.
Australian media lawyer, Nic Pullen, presents an excellent overview of the decision.
The Court of Appeal in England, however, has more recently cast doubts over the Australian High Court decision.
Richard Ackland writes about that decision here.
The lesson here is that defamation law as it pertains to the internet is still developing and you need to be careful.