Mark Shuttleworth has apologised for the sending of a cease and desist notice to Micah Lee, the man behind the fixubuntu.com site which Canonical accused of violating its Ubuntu trademark.

"Occasionally we make mistakes. When we do it’s appropriate to apologise, address them, and take steps to ensure they don’t happen again," wrote Shuttleworth in a blog post.

"Last week, someone at Canonical made a mistake in sending the wrong response to a trademark issue out of the range of responses we usually take. That has been addressed, and steps are being taken to reduce the likelihood of a future repeat."

The Canonical and Ubuntu founder said that his company is rather permissive with its trademark usage, and that a paralegal sent out the wrong template email.

"Last week, the less-than-a-month-at-Canonical new guy sent out the toughest template letter to the folks behind a 'sucks' site," Shuttleworth said. " It was a mistake, and there is no question that the various people in the line of responsibility know and agree that it was a mistake."

Shuttleworth equated the issue to a programmer inserting a bug in a piece of code, albeit the type of bug that causes catastrophic problems for the programmer concerned.

"It was no different, however, than a bug in a line of code, which I think most developers would agree happens to the best of us. It just happened to be, in that analogy, a zero-day remote root bug," he said.

"For those carrying pitchforks and torches on this issue, ask yourself if that would be appropriate to a bug in a line of code in one of many thousands of changes being made monthly by a large team. No? Think about it."

The issue blew up at over the weekend as Micah Lee, who also works at the Electronic Frontier Foundation (EFF), published the trademark notice received from Canonical on his blog. The notice demanded that Lee stop using the Ubuntu logo and use of Ubuntu in his domain name.

"Unfortunately, in this instance we cannot give you permission to use Ubuntu trademarks on your website and in your domain name as they may lead to confusion or the misunderstanding that your website is associated with Canonical or Ubuntu," the notice said.

Lee wrote that he felt his usage of the Ubuntu name and logo fell under nominative use, but decided to discontinue usage of the Ubuntu logo on his site, as well as adding a disclaimer.

"Disclaimer: In case you are either 1) a complete idiot; or 2) a lawyer; or 3) both, please be aware that this site is not affiliated with or approved by Canonical Limited. This site criticizes Canonical for certain privacy-invading features of Ubuntu and teaches users how to fix them. So, obviously, the site is not approved by Canonical. And our use of the trademarked term Ubuntu is plainly descriptive—it helps the public find this site and understand its message," Lee wrote.

Lee's fixubuntu.com site provides a simple script that Ubuntu users can run to disable the sending of search terms in Ubuntu's Dash, a universal search feature enabled by default in the Linux distribution, to third parties.

After having the EFF reply on his behalf, Canonical stated that it was happy that Lee was discontinuing usage of its logo, and considered the matter resolved.

Shuttleworth subsequently posted his apology over the matter, at the bottom of which, he also apologised for his usage of the term "Open Source Tea Party" , that he used in remarks attacking detractors of Canonical's Mir display server.

"I made a mistake myself when I used the label 'open source tea party' to refer to the vocal non-technical critics of work that Canonical does. That was unnecessary and quite possibly equally offensive to members of the real Tea Party (hi there!) and the people with vocal non-technical criticism of work that Canonical does (hello there!)," Shuttleworth wrote.

Shuttleworth stated that he was attempting to disparage people who make criticisms of Mir that is more focused on politics of Mir rather than any technical discussion about the project.

"Unless critique is focused on improving the software in question it is pretty much a waste of the time of the people who are trying to improve the software in question," he said.

"That waste of time is what I had in mind with the comment; nevertheless, it was a thoughtless use of an irrelevant label."

"Please accept my apologies if you have been a vocal non-technical critic of Canonical's software and felt offended by the label."