-26How then could it be said that the respondents “authorized” their publication? Mr Thomas’s answer is that since, for their own commercial purposes, every posting on the forum was made with the respondents’ encouragement, they must be taken to have authorized each such posting, whatever its content. 64. It is of course possible in law that a principal might attract liability where he authorizes his agent to publish whatever statement the latter may choose to publish, including a defamatory statement. However, that would have to be established as a matter of fact with evidence of some pre-existing arrangement between principal and agent or later ratification. An example where such evidence did exist can be found in Thompson v Australian Capital TV Ltd,55 where Channel 7’s decision to re-broadcast the programme made by Channel 9 instantaneously was held to be evidence of Channel 7 authorising publication of whatever content Channel 9 chose to put into that programme. Gaudron J reached that conclusion, stating: “There can be no doubt that Channel 7 authorised the retransmission to its viewers by its servants or agents of the material which was defamatory of the appellant. Without its authority, the material would not have been retransmitted. And it is sufficient that it authorised the retransmission to its viewers of whatever was transmitted by Channel 9 without regard to its contents. Having authorised its retransmission, Channel 7 published the material in question. It cannot rely on the defence of innocent dissemination.”56 65. That was of course a situation involving two television channels, each in the business of making “one-to-many” broadcasts, with one adopting the programme produced by the other. The re-transmission was pursuant to a specific mutual arrangement which was plainly evident. 66. Nothing approaching such evidence exists in the present case. It is inherently improbable that the provider of an internet platform facilitating many-to-many exchanges among users who may post as many as 5,000 55 (1996) 186 CLR 574 at 592. 56 At 596.