Patents are like the toxic waste of innovation. You promise yourself to keep them safely contained, but its hard to do in the real world and once they spill, they contaminate everything around them, making the ground uninhabitable for 20 odd years.
The patent is ATEBITS LLC's, and I understand Atebits is now a subsidiary of Twitter. So the patent would indeed be Twitter's, Loren is listed as the inventor but is not the assignee.
He probably shouldn't have been promising not to use a patent he didn't own anymore, then. Not cool, unless there's a private agreement requiring his consent for patent usage.
Either this, or negotiated/set a better expectation that he isn't going to bring certain inventions with him to Twitter. Granted, this probably would have made it harder for an agreement on terms regarding his place at Twitter to come into existence.
The correct way to do that would have been to just release it without patenting it, no? He was the first one to do it, so his prior art would invalidate any future patents, and we'd all be free to use it without any fear.
I really wish patents worked that way. Unfortunately, they don't.
If something is patented, then no one else can patent it -- that's pretty clear and the patent office enforces it fairly well. If something is "obvious" (to one of ordinary skill) or if something has already been done, then it SHOULD not be patentable... but it is quite common for such things to be patented anyway. To be fair, it is unreasonable for the patent office to know about every thing which has ever been done, but still these things get patented.
Once a patent is issued, there is a presumption by the courts that it is valid. You can contest this, and use prior art to invalidate the patent but it will require litigation and will be VERY EXPENSIVE. You can "use it without fear" as long as you don't mind paying a trivial $100,000 or more in litigation costs.
I would be very pleased if someone knowledgeable about the practice of patent law would write in to correct me -- I really wish it didn't work like this -- but from what I have seen I believe that there IS a real danger that things which have been "released" wind up patented later.
If something is patented, then no one else can patent it
I wish that were also true. In reality patents overlap hugely, and a line of trolls can form for the same feature. You have to spend the same 100k to show that another patent, issued earlier, also covered this idea, even if that patent was yours.
One solution to this problem is a defensive publication: basically you write a patent application, send it to the patent office (so they can use it as prior art), but don't ask for it to be patented. Unfortunately, writing the application has a nontrivial cost.
I'm a big believer in making incremental improvements to the patent system instead of throwing the whole thing away (which doesn't seem likely). Removing (or reducing) the nontrivial costs of these defensive publications would be a great step in the right direction. I can even imagine a campaign to file for "not-patents" on a bunch of things to definitively establish prior art to make it harder to get a bogus patent to begin with.
Yeah, I have seen this in use for some time in high profile applications - seemingly indicating that it is not being enforced.
The Android Facebook app has this pull-to-refresh on its news feed - has for the last handful of updates. Pulse News also has used this same behavior for quite some time... It would seem that either these (and others) have been overlooked or the patent is indeed not being enforced at this time.
(That said, as commenters below correctly point out, Twitter, not Loren, owns the patent and gets to decide whom to enforce it against).