The Linux community should come down from the moral high ground, says technology analyst Bill Thompson.
For the last six months computer company SCO, formerly known as Caldera International and one of the early distributors of the Linux operating system, has been causing serious concern within the world of free and open source software.
The Linux mascot is a penguin
It has sued IBM and threatened to sue Linux users and distributors over claims that large chunks of the Unix program code which it owns have been illegally copied into the current release of Linux.
If true, the copying could mean that Linux users have to pay SCO a license fee. It could also mean that the companies involved have to pay damages, even if all the offending programs are rewritten.
Of course, there may be nothing to the claims.
SCO was a struggling company before it started this high-profile action, although it has seen its share price rise significantly as investors gamble on its ability to raise money from licensing or damages.
Senior investors have been selling their shares. Their chief financial officer, Robert Bench, sold 14,000 shares in June and July, which may indicate that they think this is a temporary improvement.
So it could all be a scare story with no longer-term implications for Linux.
Certainly, the evidence SCO has put forward to prove its claim has not been impressive.
A sample of the "copied" code which it showed off at a trade show on 18 August has been ruthlessly dissected online.
It seems all of the examples are of older code which, through various routes is already in the public domain and therefore can be used in Linux without infringing SCO's rights.
However the tale is complicated, partly by the history of Unix and partly by way Linux is developed.
Since 1969, when Unix was created, there have been many versions and many owners. The telephone company, AT&T, owned the main version called Unix System V until 1993 when it sold it to Novell.
Novell sold it to the Santa Cruz Operation in 1995, which passed it to Caldera in 2002. At that point, Caldera changed its name to SCO and stopped selling its own version of Linux.
There are other versions, most notably one developed at the University of California in Berkeley, which are wholly or partly free of copyright restrictions.
It is therefore quite important to know exactly where code came from before any ownership can be claimed, and SCO seems to have failed to do this.
Since Linux is an attempt to build an operating system that would work in the same way as Unix, but be outside any corporate ownership, it is not surprising there are issues around intellectual property.
Nor is it a shock that SCO, as the owners of Unix, would take an interest.
In theory the ownership of the Linux kernel, the heart of the operating system, is clear.
In order to be accepted as part of the kernel by Linus Torvalds and the other key people controlling Linux, the thousands of developers giving their time and effort to the project have to release their code under a special software license, called the GNU Public License or GPL.
This was originally drawn up by programmer Richard Stallman, and it relies on US copyright law to ensure any programs written are made available to others to improve and use as they wish.
Any code released under the GPL must remain under the same license even if it is updated - so that if someone fixes a bug or writes a new part of the system, their new stuff is also available for everyone else to build on.
The GPL is the basis of the free software movement, of which Linux is the best known example. SCO are claiming that some programmers took code which SCO owned and released it illegally under the GPL.
The worrying thing is, there is nothing inherently implausible about this claim. There are over 30 million lines of program source in a Linux distribution, if you include all the programming tools and utilities.
Since the Unix source code is widely available inside the sorts of large companies where many Linux contributors work, someone could have decided to take a shortcut when writing a complicated section of a program and just copied it from Unix.
The Linux community, and Linus Torvalds himself, claim that the development process is already the most transparent in the whole industry.
But this relies on someone recognising that submitted code came from somewhere else.
There is no formal mechanism for ensuring that the developers are not submitting code which does not belongs to them, only this unstructured peer review and that may not be enough.
Developers have to submit code changes
Unfortunately, the typical response of a Linux user to SCO's claims has been to dismiss them. They criticise SCO for even hinting that Linux could be anything other than perfectly legal and clean, and support actions such as the recent denial of service attack on the SCO website.
Since the GPL relies on copyright law for its legal strength, it seems unwise for the Linux world to argue - as some have - that SCO should be destroyed for daring to protect its own copyright.
Instead, the developers and the team in charge of the Linux kernel should think about how they ensure that they really are respecting other people's copyrights when they accept contributions.
Linux is a great operating system, and free software is a vital alternative to the buggy systems sold by Microsoft and other large companies.
It is not perfect though, and it is not immune from copyright law just because it is morally superior.
The Linux community needs to accept that this could be a real problem, and put processes in place to make sure it cannot happen instead of simply dismissing all criticism as unfounded.
Bill Thompson is a regular commentator on the BBC World Service programme Go Digital.