Time Warner Cable's plan to impose tiered data caps on Internet users imploded last week, but that doesn't mean TWC users can download to their heart's content. No, like many other ISPs without explicit data caps, TWC retains an "acceptable use policy" that lets it curtail any "abuse" of its network, as one user found out the hard way.

StoptheCap.com has been covering the TWC case in obsessive detail (seriously, we're a little worried), and it yesterday published the story of a TWC user from Austin, Texas who ran afoul of the acceptable use policy.

Ryan Howard had his Internet connection cut off by the company with no notification; only after a full day of phone calls and two new cable modems did a service rep suggest he call TWC's "security and abuse center." Turns out, Howard had transferred 44GB of data in a single week, enough to put him in the penalty box. (He apparently violated this clause: "The ISP Service may not be used to engage in any conduct that interferes with Operator's ability to provide service to others, including the use of excessive bandwidth.")

He asked about the limit so that he could stay under it in future, but couldn't get an answer. Instead, it was suggested that he use "perhaps half or a quarter as much" data in a week.

Assuming that the trigger is somewhere around 40GB/week, that works out to 160GB/month—still a full 90GB under Comcast's 250GB/month cap. And if Howard is really supposed to use only "half or a quarter" of this amount, that means TWC imposes a de facto limit of between 40GB/month to 80GB/month.

When services like Netflix require 3GB just to stream one high-def movie to an Xbox 360, it's not hard to see how a household with a few computers, a game console, and (say) an iPhone might hit such caps without doing anything piratical or "abusive."

Such practices aren't limited to TWC, of course. While ISPs like Comcast have adopted explicit caps, others like AT&T have not, even though they reserve the right to curtail abuse on the network. Given the importance of an Internet connection for everything from telecommuting to entertainment to phone service to e-mail to keeping up on politics, this is one of those areas where ambiguity should give way to clarity. People simply need to know what's allowed and what's not.

ISPs have sometimes tried to solve the problem by calling people first and asking them to rein it in, an approach far preferable to simply shutting off someone's Internet access after they hit some unpublished threshold.

This isn't just pro-consumer—it's pro-business, too, unless you're in a business that enjoys lawsuits. Comcast last year paid the state of Florida $150,000 to deal with this exact issue and the ambiguity that surrounded it. Each month, Comcast would contact the top 1,000 users of its 14.4 million user network network, regardless of how much data they had transferred, and warn them that they were violating the acceptable use policy. When users asked what the limit was, they were simply told that they needed to stay out of the top 1,000 user list—something impossible to know.

The state attorney general said that "a 'top 1,000' criteria, as previously applied, did not clearly and conspicuously disclose to the consumer the specific amount of bandwidth deemed to be excessive under Comcast's subscriber agreements." In response, Comcast adopted the explicit 250GB/month cap.

In any event, whatever the realities of traffic on TWC's data network, the cable company's situation just can't be all that dire. As StoptheCap.com noted today, TWC has just given San Antonio users a free bandwidth upgrade from 10Mbps to 15Mbps—basically begging them to transfer more data in a month.