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.
