WIRED ON FRIDAY:It takes a particular kind of brazen confidence to assert you're not messing with your customers' internet access, when any one of those customers can test that assertion and show you up. But what happens when these meddlers are finally exposed?

Will they stop? Will they find a better solution to their problems? Or will they just pray that the limited competition in the broadband ISP market will let you get away with such consumer-unfriendly behaviour?

Three months ago, Comcast, a cable internet provider in the United States, pointedly denied accusations that it was faking internet packets from its users to deliberately shut down certain net connections.

Comcast customers had noticed that when they used BitTorrent, a popular file distribution protocol, their connections would be frequently curtailed. Users on other ISPs didn't see the same problems - unless they were connecting to Comcast customers, in which case their connectivity was abruptly broken too.

Only BitTorrent protocols were affected and, if the users disguised their BitTorrent sessions using cryptography, the problem went away.

For three months, Comcast huffily denied there was a problem and insisted it was not "deliberately blocking, degrading, interfering with, or discriminating against particular protocols or kinds of traffic".

This week, Comcast had to back down after its own users had a put the lie to it. An AP journalist, using BitTorrent to download the King James Bible, monitored exactly the kind of connection crippling that the company had denied.

Plenty of ISPs already meddle with their customer's communications.

If you have tried to send mail from your home computer without going through your net provider's default mail server, you may have had problems as many ISPs block outgoing e-mail from their users to prevent malware from sending spam.

Other internet providers "traffic shape", which involves deliberately throttling the speed of file-sharing protocols compared to other traffic, such as voice-over-IP (internet telephones) or normal web traffic.

What Comcast did, however, was over and above simple blocking or throttling. When its users attempted to use BitTorrent, Comcast faked a part of the communication itself, essentially masquerading as both parties in the communication, and telling each of them that the other was "hanging up" the call.

It also kept this policy secret from its users and even publicly denied any wrongdoing when the problem was first spotted by customers three months ago.

The irony of this is that BitTorrent is one of the more copyright-friendly protocols. It was designed to help share the load of downloading large files that might otherwise cost a single provider a lot of money to offer.

Many Hollywood companies are experimenting with using it to transmit their own content.

Software houses regularly use BitTorrent to provide software and send updates to their users. Linux is distributed to developers and clients over BitTorrent.

Meddling with end-users' communications like this is at best a short-term gain for the ISPs. It is fairly simple to encrypt communications to evade such blocks; slightly harder, but not spectacularly harder, to disguise the protocol as another, such as that used by the web or instant messaging.

The more ISPs attempt to control their users' behaviour, the more that behaviour will go underground.

It will also become more inefficient and put even greater strains on the ISPs provisioning.

It is also disturbing to see any intermediary intervene so directly in a third-party's communications.

We wouldn't expect the phone companies to demand to control what we said on the telephone or monitor us to make sure we were not plotting crimes or hanging us up when they suspected we were.

It's this kind of encroachment on the idea of a private internet - that you can communicate freely with others online, without being scanned, analysed, data mined or logged by intermediaries - that needs to be closely monitored.

There are less intrusive ways to keep a network up. If they are really worried about bandwidth, Comcast could publish public bandwidth "caps" within which their home consumers would have to work.

As a cable company, it is more likely that Comcast is not short of bandwidth to the rest of the internet; its problems come from clumsily attempting to handle poor resource-sharing closer to the end user.

Because of the way that cable internet divides bandwidth between a number of users on a street, someone using all of their broadband allocation can slow things down for everyone else nearby.

The answer, long term, is better sharing (and either providing more bandwidth, or being more honest in describing how much bandwidth you can provider). Right now, it happens that the majority of bandwidth "hogs" are a group that is already publicly scorned - file sharers.

But BitTorrent is just one of the first of many legitimate bandwidth-intensive applications. Peer-to-peer services such as Skype (the telephone service) and Joost (a peer-to-peer TV company) can already take up just as much bandwidth, and there's no shady copyright-infringing for Comcast or others to blame.

In the end, it will have to admit that it is messing with private communications and commerce or come clean about the limits of its network.

I'm not holding my breath for either.