It occurs to me that this article, published in February 2013, may be of interest:

http://www.bbc.co.uk/news/magazine-20782257

It also gives some indication as to why we have to be careful on this site, too.

It belies the belief that many people are under the mistaken assumption that there
is safety being part of a mob making defaming remarks.
Watch what you say in the heat of the moment, it could come back to bite you in the [censored].

And a bite in the (censored) is really painful....;)

I have had a long time(30+ years) interest in the law. It varies from country to country. I checked out the link, a bit heavy for me at the time. I do see how many can use weaknesses, misinterpretation, and subjective thinking to get in `a bit of trouble'.
I also know about the law here in Canada. There is a `safe harbor' provision that protects those that are at least `somewhat ignorant' but, who will be these `right thinking people'?

I am more concerned about the actions of the world at large. Social media? Well, some are not gullible dolts, sheep, but so many are.

Would harsh criticism be violating libel laws? There is also an `ought to know' part in Canadian law. A reasonably sane and experienced adult would be expected to know `basic elements' of the law that relate to `common sense'

Worth reading more about, but I have little fear as far as I am concerned. I guess reposted rumors can be likened to gossip, and that can be malicious, and hurt people, true.
I consider that source.

later, Gov!