Innocent dissemination

A person who is found to have published a defamatory statement may evoke a defence of innocent dissemination, which absolves him/her of liability provided that he/she had no knowledge of the defamatory nature of the statement, and that his/her failure to detect the defamatory content was not due to negligence. The defence, sometimes also known as "mechanical distributor", is of concern to Internet Service Providers because of their potential liability for defamatory material posted by their subscribers.

The basic rule is that everyone involved in any way in the production or dissemination of defamatory material is liable as having published it. This is because defamation is a tort of strict liability. It can be committed unwittingly by reason of the existence of facts and circumstances unknown to the publisher of the defamatory statement. However, some forms of distribution or dissemination are so mechanical that a distributor ought not to be held liable unless he/she ought to have known there was defamation involved. Therefore, a defence of innocent dissemination is conceived

At common law, a defense of innocent dissemination is available to a person who, neither knowingly nor negligently, had merely a subordinate role in the dissemination of the matter containing the defamatory statement.

In Vizetelly v. Mudie's Select Library, a circulating library provided to subscribers a book on Stanley's search for Emir Pasha in Africa, which turned out to be defamatory. The issue was whether the library can claim protection under innocent dissemination. Lord Justice Romer described the defence as follows:

That [they were] innocent of any knowledge of the libel contained in the work disseminated by [them], that there was nothing in the work or the circumstances under which it came to [them] which ought to have led [them] to suppose that it contained a libel, and that, when the work was disseminated by [them], it was not by any negligence on [their] part that [they] did not know that it contained the libel, then, although the dissemination of the work by [them] was primâ facie publication of it, [they] may nevertheless, on proof of the before-mentioned facts, be held not to have published it.

Romer L.J., at 180, also noted that the defence places a heavy burden upon the defendant to show that they were not negligent. His Lordship held that the defendant library was liable for having negligently overlooked the publisher's request for return of the offending book.

Therefore, the defence involves three limbs:

However, it appears that a printer cannot evoke this defence. This has been criticized as "illogical" and has been explained as an exception that made sense in the days of primitive technology only - when printers used to read what they print, which is no longer the case.

...
Wikipedia