## Background: Kootol Patent

A company called Kootol has recently been in the news advertising their ownership of U.S. Patent Application No. 20100030734, which will very probably soon be issued.

Kootol has given notice to various companies that they are likely to be infringing on this patent when it is issued.

The most significant alleged future infringer appears to be Twitter, and some of the other companies involved are developers of Twitter clients.

## Prior Art: Miski

In 2000, I developed an idea for an internet messaging system called Miski. An important proof of priority is this copy of my original web page as captured on Wayback in February 2001.

In considering the relevance of prior art to a specific infringement claim, there is a three-way relationship between three items:

1. The patent
2. The (possible) prior art
3. The alleged infringing technology

Firstly the dates have to be in the right order, in this case:

- The prior art, presumably published 3 June 2000 (since that is the date I wrote in the web page), and provably published on or before 23 February 2001, i.e. the date of the first Wayback capture of that page.
- The patent, which has a priority date of 22 July 2005.
- The allegedly infringing technology, in this case Twitter, which, according to Wikipedia was launched in July 2006.

In considering the three items, the important relationships are the degrees of overlap:

- In as much as the technology overlaps the patent claims, it may be infringing on the patent.
- In as much as the prior art overlaps the patent claims, those patent claims may not be upheld.
- In as much as the prior art overlaps the technology, the prior art may "protect" the technology from infringement action.

Furthermore, in as much as the patent claims may be difficult to interpret, the last of those three relationships may be better defined than the first two.

## Comparison of Twitter and Miski

On the one hand Twitter is an implemented technology which millions of people use. On the other hand Miski is an unimplemented plan for a technology which exists only as a web page on a SourceForge project which has since been closed.

The only advantage that Miski has over Twitter is that it appeared earlier than Twitter. In the legal world of patents, date is everything.

There are significant similarities between Miski and Twitter, which I think are strong enough to make Miski an important item of prior art with regards to the Kootol patent.

In particular:

- There are users, each user with a unique user ID.
- Users post messages.
- Users subscribe to other users.
- Subscribers receive all messages posted by the users that they subscribe to, in something close to real-time.
- Subscribers may repost (aka "retweet") messages so that their subscribers receive them.

Signficant differences are:

- Twitter has a single server, and all usernames exist within that server. (The implementation of course can have multiple physical servers, but there is only one domain name involved, i.e. twitter.com.)
- Twitter messages can be any text within a 140 character limit, which may contain web links.
- All Miski messages are web URLs. It is assumed that content would be hosted elsewhere as decided by the posting user.
- Twitter retweets are new messages with the same content. In Miski the URL is the message, so a repost is in some sense the same message, and I described a de-duplication process so that subscribers did not need to see multiple copies of the same posted URL.

## Comparing Twitter and Miski to the Kootol Patent

The similarities between Twitter and Miski are relatively obvious. Whether or not either of these two systems is similar to any of the claims in the Kootol Patent is not so obvious, and I will leave that as an exercise for the reader.

Update (3 August 2011): I recently encountered this page on the Software Patents wiki which mentions three patents held by TechRadium for contacting people in an emergency. TechRadium sued Twitter for patent infringement as Twitter was being used for the purpose of contacting people in an emergency (I don't know what the outcome of that legal action was). The three patents appear to be refinements of the same invention; the earliest one was filed 28 April 2005.