All the main BBC television networks will be streamed online for the first time with the addition of the two main channels this week. Officially it is part of a 12-month trial, although it seems likely to become a permanent service. A new survey suggests the BBC iPlayer is incredibly popular among the online population. Once again this has raised questions about the long-term enforceability of the television licence in the United Kingdom.

BBC One and BBC Two will join BBC Three, BBC Four, CBBC, CBeebies and BBC News, which are already simulcast online.

“The launch of BBC One and BBC Two online completes our commitment to make our portfolio of channels available to watch on the internet,” said Jana Bennet, director of BBC Vision. “From 27 November licence fee payers will be able to watch BBC programmes, live, wherever they are in the UK on their computers, mobile phones and other portable devices.”

The BBC iPlayer has already proved incredibly popular. A recent online survey of over 1,000 people conducted by YouGov for law firm Olswang found that 24% of respondents claimed to stream or download television programmes using the BBC iPlayer for at least one hour every week. A further 26% said that they used it at least once a week.

While 40% said they chose not to do this, and 9% said they did not have the capability to, only 2% of those surveyed did not understand the concept.

“iPlayer has been the catalyst to transform online TV from a minority interest into a daily activity, much as iPod and iTunes did for digital music,” said John Enser, media, communications and technology partner at Olswang.

The number claiming to use legitimate online video services other than the iPlayer to stream or download television programmes for more than an hour a week was significantly lower, at 17%, while 9% admitted to using illicit services.

The usual caveat applies that this was an online survey, so may over represent those that are more technologically enabled. The self-reporting methodology may also exaggerate claimed usage.

The BBC says the live streams will be restricted so they cannot be viewed from outside the United Kingdom. So-called GEO-IP filtering will be used to limit streams to internet addresses known to be based within the United Kingdom.

The corporation also points out that anyone in the United Kingdom watching or recording television as it is being broadcast must be covered by a television licence. Legally, a TV licence must be held obtained to cover any device that is “installed or used” for “receiving a television programme at the same time (or virtually the same time) as it is received by members of the public”.

This has prompted predictable complaints that the £139.50 annual television licence fee will become an unenforceable funding mechanism in the future. This is a matter of routine for some newspapers that have long been critical of the television licence, but even The Independent has carried an editorial saying “It may well be unsustainable over the long- or even medium-term future”.

Around one in 20 households is estimated to evade paying the television licence. An average of 1,000 evaders are caught every day as a result of 3.5 million visits to premises every year. Last year saw the introduction of new handheld detectors developed by the BBC, little bigger than a torch, which can be used to track down televisions at addresses without a licence.

The BBC, which outsources licence fee collection through an organisation known as TV Licensing, told The Sunday Times that it has not developed any new detection methodsto deal with online viewing. There seems to be some confusion about what it technically and legally possible.

“How will they know what you’ve used your computer for?” said John Whittingdale, chairman of the Commons media select committee. Well, one might imagine that logs of the IP addresses used for GEO-IP filtering would provide ample conveniently time-stamped evidence. However, many IP addresses are dynamically allocated by network service providers, so relating them to customer accounts would require alo access to their logs.

A representative for BT said they would not provide such customer data. “We don’t do it for file sharing and music piracy, and we wouldn’t do it for the BBC. They have to come to us with a court order and an IP address. Then and only then would we divulge an individual’s details.” So that’s clear.