Captain Copyright, a Canadian "education" site about copyright — aimed at conveying a pro-copyright message to children, and at being used by schoolteachers for that purpose — has the following "Legal Notice":
Links from Other Web Sites ...
Permission is expressly granted to any person who wishes to place a link in his or her own web site to www.accesscopyright.ca or any of its pages with the following exception: permission to link is explicitly withheld from any web site the contents of which may, in the opinion of the Access Copyright, be damaging or cause harm to the reputation of, Access Copyright. In the event we contact you and request the link be removed, you agree to comply with that request promptly. If you link to or otherwise include www.accesscopyright.ca on your website, please let us know and create any link to our home page only.
Under U.S. law, no-one needs permission to link to another site; your bitterest enemy is free to link to your site even if you insist that the link be removed. Nor is simply placing a paragraph on the Web page saying that "you agree to comply with that request promptly" sufficient to impose any contractual obligation on you. (Even the shrinkwrap licensing cases don't go that far.) I'm not an expert on Canadian copyright law, but Prof. Michael Geist, who is an expert on the subject (and whose column alerted me to the issue) describes Canadian law the same way.
In any case, I'm sending the following message to the address posted on the site (privacy at accesscopyright.ca):
Dear Madam or Sir:
I wanted to inform you that I've linked to your site at http://volokh.com/archives/archive_2006_06_11-2006_06_17.shtml#1150217780, a post on a Weblog that gets about 15,000 unique visitors per day. The link is quite critical, and I hope that it will (justifiably) harm your reputation: I point out that your "Links from Other Web Sites" policy is legally unenforceable, implicitly misstates the law in ways that may mislead lay readers (including children and schoolteachers who are visiting your site), and therefore casts doubt on the credibility of the "educational" material you post on your site.
Should you request or demand that I remove the link, I will categorically refuse, as I am entirely within my rights to do. Copyright law does not restrict my linking to your site, and because I never expressed agreement to the offered terms on your site, I am not contractually bound by your assertions of your supposed rights, either. I have absolutely no intention of complying with your requests. Rather, I intend to continue to link to your site in ways that injure your reputation.
Professor of Law
UCLA School of Law
(affiliation listed for identification purposes only; I speak for myself, not for my institution)
Proprietor, The Volokh Conspiracy, http://volokh.com
UPDATE: Commenter Michael Barclay reports that the site has very recently (since I visited it and copied the material quoted above) changed its policy slightly to say:
Permission is expressly granted to any person who wishes to place a link in his or her own website to www.accesscopyright.ca or any of its pages with the following exception: permission to link is explicitly withheld from any website the contents of which may, in the opinion of the Access Copyright, be damaging or cause harm to the reputation of Access Copyright. Specifically, permission to link is explicitly withheld from sites featuring pornographic, racist or homophobic content. If you link to or otherwise include www.captaincopyright.ca on your website, please let us know.My criticism of the policy still stands.