The document, which governs acceptable uses for the company's cable-modem service Comcast@Home, was recently updated for the third time. The new version, in section 6B, requires subscribers to agree not to use the service as a means to create what is known as a virtual private network, or VPN--a technology that provides a secure connection across the Internet.
Comcast representatives said the decision was based upon the service's intended use as a residential online service, rather than as commercial Internet access. Excite@Home, and its cable operator partners such as Comcast, Cox Communications and AT&T have struggled with the balance between offering high-speed Net access for casual Web surfers and curtailing abuses of the bandwidth by businesses and customers running high-powered computer servers off a cable-modem connection.
The companies are wary of customers who purchase a cable-modem connection only to use it for business purposes, potentially as a Net access line for several employees or as a conduit for a Web site.
VPNs provide secure connections across the public Internet to link businesses or consumers with a remote location. Many telecommuters use the technology to access corporate email or other files from home.
"We just had never clarified in the last agreement about VPNs," said Suzanne McFadden, director of marketing for Comcast Online. "Basically what we're doing is just putting in some rules that go along with what we've always said, and that is that Comcast@Home is a residential service only."
Comcast believes average consumers, not businesses looking for low-cost Net access, should use its service.
"People using it for business use really should be on a different type of product. It really is just a residential product," McFadden said.
In emails to CNET News.com, customers said they understand that Comcast and Excite@Home need to prevent a handful of abusers from hogging the bandwidth for themselves. But limiting the level of service for honest customers is frustrating, they said.
"This probably only affects a small minority of people who access Web sites that are restricted from the general public by a VPN gateway and, unfortunately, that's me," one Comcast customer said in an email.
"The entire tone is to restrict people from Web hosting or running a business using @Home service. Then at the end it makes a blanket statement about VPN that can be taken either way, i.e., you can't run a VPN at home, and you can't talk to one anywhere else," the customer said.
"The penalty for violating this is, of course, termination of your account," the person wrote.
Another said: "I don't understand why, since VPNs are great for telecommuting. Is this just another instance of @Home giving and @Home taking away?"
The move by Comcast@Home raises the hackles of those who believe the service is not what they originally paid for. For example, the service upload speeds were throttled back last year in an effort to thwart bandwidth abusers. Some customers spoke out, complaining that a few "bad apples" shouldn't affect the service for everyone else.
Excite@Home, the Internet service provider that works with the cable operators to provide cable-modem service, stands by Comcast's new customer agreement.
"We believe in offering the best possible service to all @Home users, and we support efforts undertaken by our (cable) partners that are designed to accomplish that goal," said an Excite@Home spokesman.
The VPN issue is not the first time changes to an Excite@Home terms-of-service document have angered some customers.
In February, Tele-Communications Inc.--now part of AT&T--revised its acceptable use policies in such a way that some subscribers were concerned the company could publish or sell the contents of their email or any other information transmitted via the TCI@Home service.
TCI wrote a letter to its customers addressing their privacy concerns.