Teluss one million subscribers were also barred from reading an additional 766 web sites sites that are hosted by the same server as the pro-union site, but are otherwise unrelated.

Whats more, one legal expert says, Teluss action could come back to haunt the company and all other Canadian Internet Service Providers (ISPs).

Last week, Telus blocked its subscribers from accessing Voices For Change, a Web site run by locked-out Telus employee David DiMaria. At the time, the company argued that photographs posted on the site threatened the safety of persons crossing Telecommunications Workers Union picket lines. Telus later restored access to the Web site after obtaining an injunction that prohibited the posting of photos that might intimidate or threaten anyone connected with the dispute.

(Telus also blocked a second site, telusscabs.ca, which appears to no longer exist.)

A report from the OpenNet Initiative notes that Telus blocked Voices For Change by cutting off all access to the Florida-based server that hosts the site. That meant that Telus customers were unable to access any of the 766 unrelated Web sites that are also hosted on the same server.

The blocked sites include an engineering company, an Australian-based site promoting alternative medicine, a Colorado company that recycles electronics parts, and a fundraising site for breast cancer research.

The OpenNet Initiative is a partnership between the University of Torontos Citizen Lab, the Berkman Center for Internet & Society at Harvard Law School, and the Advanced Network Research Group at the Cambridge Security Programme at Cambridge University. Much of its work involves studies of Internet blocking by authoritarian regimes around the world.

Ronald Deibert, a University of Toronto associate professor and director of the Citizen Lab, said Wednesday that the Telus action is troubling.

Certainly, it raises some very serious questions about whether a private company can arbitrarily and in an unaccountable manner just simply shut off access to information. This is the type of thing that goes on in China, not what we would expect in a country like Canada.

Deiberts report says Teluss action raises significant legal, ethical and practical questions.

As this case demonstrates, seemingly compartmentalized decisions to block access to Internet content can have drastic unintended consequences, barring Internet users from reaching hundreds of unassociated Web sites. ISPs can unilaterally block access to large swaths of content with the flick of a switch.

By collaterally blocking hundreds of completely unrelated sites, Telus has vividly demonstrated the dangers of Internet filtering, particularly when it is conducted in an arbitrary and unaccountable manner.

It is impossible to tell how many Telus subscribers were in fact prevented from reading any of the blocked sites, but Deibert said the question is beside the point.

If just one person is denied access, thats significant, he said. The real question, he said, is this: Should private entities that are providing Internet services be allowed to arbitrarily decide what type of sites their customers can or cannot access?

Richard Rosenberg, vice-president of Electronic Frontier Canada, said Teluss action is contrary to ISPs traditional reluctance to become involved with content.

Theres this tradition that the ISPs early on in the development of the Web wanted little to know about the content because they were worried that if they had some responsibility for content, this would mean legal responsibilities, said Rosenberg, professor emeritus of computer science at the University of B.C.

For the Internet its really an awful thing if ISPs play this activist role, especially in their own self interest.

In fact, says a University of Ottawa law professor, Teluss action could lead the federal government to change the way ISPs are regulated.

Although Canadian laws surrounding access to the Internet are somewhat murky, the blockage raises some significant questions, Michael Geist, Canada Research Chair in Internet and E-commerce Law, told The Tyee Wednesday.

In the past, ISPs such as Telus argued that they served the role of a common carrier, similar to telephone companies, which are not liable for the content of calls made on their telephones.

Geist said this neutral approach has allowed ISPs to be specifically exempted from legal liability under the Canadian Human Rights Act and child pornography legislation.

As neutral carriers, ISPs in the past have blocked sites only after being ordered to do so by a court. But by unilaterally moving to block access to Voices For Change before a court issued an order, Geist said, Telus appears to have taken a step away from that neutral approach.

So far, the Canadian Radio-television and Telecommunications Commission has largely taken a hands-off approach to the Internet. But Teluss action may lead the commission to revisit that decision, Geist said.

I think all ISPs may live to regret Teluss actions. This is one ISP thats acted in this way but in reality the potential regulatory implications will affect all Canadian ISPs, not just Telus.

Despite the CRTCs hands-off decision, there appears to be legal authority for intervention under the Canadian Telecommunications Act, Geist said.

Section 27(2) of the act, for example, prohibits unjust discrimination in the provision of a telecommunication service.

Section 36 states that a Canadian carrier shall not control the content or influence the meaning or purpose of telecommunications carried by it for the public.

Ottawa is already reviewing a broad range of issues related to telecommunications policy and the Telus issue may well affect the outcome of that review, Geist said.

The long-term implications of this will go well beyond the immediate blocking of this web site, Geist said.

Drew McArthur, Telus vice-president of corporate affairs, said Wednesday that it is wrong to characterize the companys actions as those of an ISP blocking a Web site.

This was not an independent ISP making a judgment call, he said. This was a company that was protecting the safety of its employees.

McArthur added that it is incorrect to compare blocking Voices For Change to the blocking of other objectionable material, such as a child pornography site.

Telus, he said, was in a very unique position in these circumstances.