The Supreme Court of Canada has ruled that inserting a hyperlink does not constitute re-publishing (Crookes v Newton).
Justice Abella wrote:
Hyperlinks thus share the same relationship with the content to which they refer as do references. Both communicate that something exists, but do not, by themselves, communicate its content. And they both require some act on the part of a third party before he or she gains access to the content. The fact that access to that content is far easier with hyperlinks than with footnotes does not change the reality that a hyperlink, by itself, is content neutral – it expresses no opinion, nor does it have any control over, the content to which it refers.
There is much equivocation in the ruling, so it cannot be regarded as a full victory of reason – but it is close. And it clearly states that one should err on the side f not restricting free speech:
To prove the publication element of defamation, a plaintiff must establish that the defendant has, by any act, conveyed defamatory meaning to a single third party who has received it. Traditionally, the form the defendant’s act takes and the manner in which it assists in causing the defamatory content to reach the third party are irrelevant. Applying this traditional rule to hyperlinks, however, would have the effect of creating a presumption of liability for all hyperlinkers. This would seriously restrict the flow of information on the Internet and, as a result, freedom of expression. (my emphasis)
UPDATE: Ezra Levant has an opinion, too: