U.S. Internet service provider Comcast appears to be run by ham-fisted executives who are actively blocking users of BitTorrent, eDonkey and Gnutella peer-to-peer software.

In fairness to the honchos at Comcast, we should look at it from their point of view.

File-sharing chews up considerably more than half the traffic on the Internet, and file-sharers, using such services as BitTorrent, are in a small minority. As an ISP, Comcast is placed in an awkward position: File-sharing traffic on such a scale slows down all their services, and interferes with the activity of people who are not file-sharers. Whatever Internet telephone services Comcast is selling or contemplating to sell will be choked; customers will not put up with delays in voice communications. All ISPs are affected by this. Rogers, Telus and Sympatico have been wrestling with file-sharing users for years.

So should Comcast force some of their customers off the Net?

ISPs need more bandwidth for their burgeoning services and for the increasing demands of a clientele in hot pursuit of multimedia. So they have a choice: either buy more bandwidth from their backbone supplier or try to discriminate between file-sharing and other traffic, and apply the brakes to the file-sharers.

An Ontario company called Sandvine created a service that “shapes” the traffic, giving top priority to things such as Internet telephones and entertainment supplied by the ISPs, and delaying non-immediate needs such as e-mail or file-sharing. This already happens by default: e-mail users don’t complain much when they have to wait a little for their e-mail, and BitTorrent users are accustomed to long waits for their downloads to finish.

The problem for the ISPs is that this is where shareholder value messes up the equation.

Given a choice between upsetting a small (though exceedingly vocal) number of customers or their own shareholders, ISPs will be tempted to opt for upsetting their customers every time.

The trick, however, is for ISPs to do it without drawing too much attention to themselves.

The issue has been extremely politicized, with anti-shaping forces calling for “Net neutrality,” meaning every byte that travels on the service should be treated equally whether it carries voice calls or Radiohead’s music. Both sides have a point: ISPs lose profit with Net neutrality, and Net neutralists worry that the bandwidth-shaping tools will be used for evil purposes, such slowing or even blocking file-sharing, which is no longer solely in the camp of music swapping, but rapidly becoming a legitimate corporate tool.

Most ISPs wisely opt for a balanced approach, slowing traffic for such things as e-mail and file-sharing, and tinker with the mix to reach an optimum point between the demands of their customers and those of their shareholders. And when the demand gets great enough, they buy more bandwidth to satisfy their customers. Land-line telephone companies have been doing this for decades; regrettably, cable companies have only recently entered the telephone field and are just beginning to learn that lesson.

The problem in the Comcast case is that the company decided to actually stop BitTorrent uploads, and then send the users a spoofed message, which looks like it comes from the other computer, telling it to stop communicating. This is underhanded, and by sending such a message, Comcast is lying to its customers. Given the contempt with which many people hold their ISPs, it’s dangerous to upset their customers further.

If Comcast is run by people who are not totally isolated from their customers, they should respond to the inevitable furor by moderating their traffic shaping and perhaps shelling out for a little more bandwidth. This they will have to do anyway sooner or later: Legitimate Internet traffic in a multimedia-mad world is growing by the day, and placing a heavy load on ISPs.

Yes, bandwidth shaping technology allows ISPs to become monolithic and monopolistic.

But just as owning a gun doesn’t give you the right to threaten anyone with it, Comcast and other ISPs owning shaping technology should not use it to abuse their customers.