Different standerds of ethics for TV and web?
[short version: Problem is not the images of violence but journalisms failure to contextualise them]

The South African Broadcasting Corporation was found guilty of contravening the broadcasting code for airing footage of the beheading of a hostage in Iraq.
The Broadcasting Complaints Commission of SA fined the SABC R15 000 for broadcasting the beheading on its Nguni television news.

However the Mail & Guardian Online, one of South Africas most prestigious newspapers, says in its blog that it would...

link to a video stream of the beheadings -- and may still do so in the near future. Our publication would ensure that such a link has the required warnings for our sensitive users. However, I wouldn't necessarily do the same thing on a TV channel: A TV is linear medium, therefore a viewer has much less choice than a web user, even though a TV viewer could ultimately turn the TV off or flip channels. The SABC was wrong to broadcast the beheadings....

Watching the video stream via the web is more an act of commission, whereas via a TV broadcast it is more an act of ommission. By actively clicking on the link we provide to the video stream, the user is making more of a conscious choice to view what is behind the link and therefore, we feel is taking a greater responsibility...

Most importantly however, we would link to the stream, because it is newsworthy and brings home the horror and chaos on the ground in Iraq, contrary to what many politicians are saying. (my italics)

So the question must be asked: If a story is newsworthy and important, why should there be a difference in publishing ethics? The choice arguement fails I believe because the newsreader could give a warning about the nature of the comming clip. And in reporting a war there will be horrific scenes shown.

Codes of ethics differ from country to country. This is to be expected. In Sweden it is unethical to publish the name and photograph of suspected (and often in fact convicted) criminals.
In the UK it is considered unethical not to publish the names and pictures of suspected criminals.
The issue is of course complicated by the global nature of the internet.
But to have seperate codes for different media? I think not.
From my point of view the problem is not that the media show graphic images of war, but that we have consistantly failed to contextualise the images. We must provide more dispassionate analysis of the hows and whys. Whether on the web or Tv. At present the "terrorists are barbarians" and "evil" (Tony Blair on Beslan: It is evil that was, until it happened, beyond the contemplation of anyone.) seems to be the norm especially in the US and British media.
This brings me back to the problem of us/them that I touched on in my earlier post on the Russian media.
We need once again to understand that "the primary purpose of journalism is to provide citizens with the information they need to be free and self-governing." We do not fulfill this obligation by seeing to it that "our" side gets the good press and in fact are being unpatriotic if we do not give our public the possibility to make informed choices.