I celebrate the impulse that gives rise to this, but I am skeptical that it will work in the long run. The reason why is that these sort of documents are social contracts just as much as they are legal contracts - this is Twitter saying publicly that they won't be evil with their patents.
The problem is that this document has enough loopholes that it only slightly ties the hands of the patent assignee (Twitter, in this case). I understand perfectly why those loopholes are there, but I think that this will backfire at some point in the future when there is a "defensive" use that, at least from the outside, doesn't appear defensive. It could be because there is a perceived threat, it could be because the inventor agrees, it doesn't matter. At that point, the legal agreement will be kept, but the social agreement broken, and that will be devastating.
The most clever bit here is that this agreement is designed to run with the patent so that it makes the patents less likely to be asserted when they are sold. That is a good thing.
As it is, though, my favorite tool for this sort of thing is the Apache license. That allows everyone who is playing nicely in the sandbox to do so - but it also allows the patents to be cross-licensed effectively and defensively asserted against existing litigation.
The problem is that this document has enough loopholes that it only slightly ties the hands of the patent assignee (Twitter, in this case). I understand perfectly why those loopholes are there, but I think that this will backfire at some point in the future when there is a "defensive" use that, at least from the outside, doesn't appear defensive. It could be because there is a perceived threat, it could be because the inventor agrees, it doesn't matter. At that point, the legal agreement will be kept, but the social agreement broken, and that will be devastating.
The most clever bit here is that this agreement is designed to run with the patent so that it makes the patents less likely to be asserted when they are sold. That is a good thing.
As it is, though, my favorite tool for this sort of thing is the Apache license. That allows everyone who is playing nicely in the sandbox to do so - but it also allows the patents to be cross-licensed effectively and defensively asserted against existing litigation.