An excellent comment by Michael Geist on Crookes v Newton:

This decision is amongst the most important the Supreme Court has issued involving the Internet. The court again demonstrates that it recognizes the importance of the Internet for freedom of expression and for the need to promote the ability to use the technology to disseminate information. The court clearly understood both the importance of linking as well as the technology behind a link. The decision rightly places responsibility for defamatory speech where it belongs – with the person who posted the content. There is still the ability to commence legal action against that person, but subjecting anyone that links to allegedly defamatory content to potential liability would have been very dangerous.