The prominent free software advocate Richard Stallman has launched a surprise attack on the Ubuntu Linux operating system, likening it to “spyware” and urging a South American free software association not to promote it anymore.

Stallman’s outburst follows the October release of Ubuntu version 12.10 last October, which features integrated Amazon search within its Dash desktop search bar. As part of that integration, Ubuntu now collects data on its user’s desktop search activity and forwards this to Amazon, a move that prompted Stallman to accuse the OS of “spying on its users”.

Canonical, the company that develops Ubuntu, has been heavily criticized for integrating the ‘feature’, despite its protestations that all user data is anonymized before being sent to Amazon. The developer says that people can choose to opt out of the service, but nevertheless dozens of angry Ubuntu users have complained that they are now being bombarded by Amazon ads in response to general desktop queries.

Upset with the move, Stallman requested that the Festival Latinoamericano de Instalación de Software Libre (FLISOL) organization stop promoting the Ubuntu OS at its events, a request that was flatly denied on the basis that is limits user’s freedom of choice. In response, Stallman fired off an angry retort to the organization’s entire mailing list last Sunday night. Parts of the email were posted on the website Groklaw earlier today:

“The issue I raise is about what should happen at FLISOL events. Give away copies of Ubuntu or not? Promote Ubuntu or no? I asked the organizers of the event that they, as a policy, not distribute or promote Ubuntu.

“Freedom of users is something else, and there isn’t a conflict between a user’s freedom and my request. If someone decides to install Ubuntu, I would consider it a mistake, but it’s his own choice to do it. What I ask is that you don’t participate, help or suggest that he do it. I didn’t request that you block him from doing so.

“As a matter of principle, I don’t believe anyone has a right, morally, to distribute proprietary software, that is, software that deprives the users of freedom. When the user controls his own software, he can install what he wants and no one can stop him. But today’s issue isn’t about him, what he does, but rather what you do with him.”

The email was only sent out last night, so it’s a bit early to tell if he will get kind of reaction he’s hoping for, though one would imagine that FLISOL dropping Ubuntu would be a pretty shocking move to make. Even so, as the founder and president of the Free Software Foundation and the author of the General Public License, Stallman is a very influential voice in the free software community, and while the points he makes might seem a bit trivial, it wouldn’t be a big surprise if people started paying attention to what he’s saying.