If you see a patent in the application pipeline that you know is bogus (obvious or prior art), you can do a preissuance submission:
I challenged a patent application and it was rejected. Now, I can't say if the patent examiner already knew that the patent was both obvious and had prior art, or if my application informed him of that, but it was rejected.
Lyon v. Boh, 1 F. 2d 48, 50 (S.D.N.Y. 1926), https://scholar.google.com/scholar_case?case=969659756696519...
In Facebook's case, though—see above—there were two final rejections. A final rejection happens when all the claims are invalidated, so your submission is now vacuous.
It's called an IPR, an inter partes review  in the USPTO. Most potential challengers, though, are likely to save their ammunition for if and when they get sued on the patent. (And they might quietly let Facebook know they have prior art, so as to discourage FB from getting aggressive — FB might want its patent to remain officially valid, so as to be able to continue to rattle its saber at others, instead of having invalidity officially confirmed.)
It's called an IPR
Obligatory warning: I'm not a patent lawyer but I've responded to both final and non-final office actions, eventually getting a patent
This sounds like it's not exactly shadow banning; your direct friends can still see your comment. I'm vaguely aware that they have special comment sections on "public" pages, articles, etc, that filter the giant thread down to stuff your friends actually wrote. I'm guessing that at some point, if you were banned from the page/etc, then your friends also couldn't see what you wrote. If that's true, then this is a little nicer to the banned user than a shadowban.
More importantly, it's more effective because it's less likely to be detected.
It still shouldn't be patentable because there's prior art involving a bunch of systems with various forms of audience selection such that how to implement this specific set of audience selection rules is obvious to most software developers. Patents cover how, not what, and they do not cover inventions whose implementation is obvious to most experts in the field.
This is (ahem) patently not true; there are plenty of patents whose implementation is incredibly obvious. Insultingly obvious. As in, "Did that company try to patent string comparison?"
Look up the "standard network byte order" patent, for instance. It's now expired and was never enforced. The friend-of-a-friend who got that patent was heard to exclaim "I can't believe they gave that patent to me!", which should tell you a lot about the quality of the patent industry then -- IMHO it hasn't changed for the better.
They should not be, and somebody should probably be lobbying congress to address the patent office not being sufficiently strict.
I'm not entirely sure why, but there appear to be perverse or at least badly aligned incentives for patent examiners, and it would appear they only look for prior art in specific locations, and these aren't the ones that the industry uses.
So you get situations like someone getting a patent for putting structures on multiple lists at a time (e.g., a lookup list, and an LRU replacement list, and maybe a list for keeping track of locks) and this is something that people have been doing since rocks were young, but some nincompoop at OraGooSoftBook got a patent on it because these structures appear in OS textbooks or maybe Knuth and not anything the examiner encountered in law school, or any legal publications. And now FaceGooSoft has a legal lock on code you wrote (hey, you did diligently read all the patents relevant to your industry before you wrote a single line, just like everybody else does right?).
More detail: https://fsfe.org/campaigns/swpat/swpat.en.html
The law should be something like just manipulating the electronic state on an otherwise non-infringing machine is never an infringement. You have to actually connect it to new hardware.
But still wasted a lot of resources which could have gone in something of real value to nature or humanity
Look at Robert Kearns. He invented the intermittent windshield wiper and demoed it to the “Big Three.” They then took his idea and implemented it themselves. So he sued them and won.
Maybe removing patents would spur innovation, but what then do you do when you’re the little guy?
Inequities in wealth and power are serious problems. Patents are a horrible method to deal with them though. If you set out to have a goal of supporting little-guy innovators, we'd do best to institute things like UBI and universal health care.
That whole windshield wiper story isn't too far from patent-trolling situations. Big companies get sued all the time by "inventors" who got patents on things that the companies would have come up with on their own anyway. The overall net effect of patents is harm for the public interest.