The extraterritorial applicability of this section would apply to them, but only to the extent of the information that they have. The duty under clause 4 to notify police arises when you have reasonable grounds to believe that a child pornography offence has been committed.
The way the couple of Internet service providers that are U.S.-based whom we've talked to are structured is that their servers are in the United States. Their corporate entity in Canada would probably never form the reasonable grounds to believe that a child pornography offence has been committed over their system until their parent company informed them. At that time, they'd be required to notify police. But really, the only information they would have is the e-mail notification that their parent company has it.
In the United States it works out well, because in the United States there is a mandatory reporting regime. The NCMEC, the National Center for Missing and Exploited Children, works hand in hand with the RCMP in Canada. It forwards any tips or any information it has to the RCMP in Canada.