Well, they are not making any use of the patent themselves, they are only trying getting some (very much) money out of it by annoying others. In this respect they are no different from a patent troll.
That's pretty much the common definition of patent troll.
http://en.wikipedia.org/wiki/Patent_troll
(Since that company doesn't seem to produce anything other than patent law suits.)
For full disclosure, I'm a student striving to become a patent attorney. I'm not at all pro patent trolls; there are some companies out there which do not benefit society or technology at all and are only out for shakedowns. However, it cannot be considered a bad thing for anyone to assert their patents if they are doing it rightfully.
In this case, it sounds like Mirror Worlds was wrong to bring the suit. Still, it shouldn't be assumed default every patent case is brought by patent trolls.
I have no interest one way or another in the result here, but HOW it happens does irritate me. Frankly, I think the whole US Court system is a load of horse manure. You think you won a case, but NO.... someone overturns it...and overturns it again and again and again and again.... WTF!?!? In criminal cases where you've won your innocence, that's called DOUBLE JEOPARDY and it's illegal (as it should be). I can understand appeals the other way around since we've proven jury trials get it wrong more often than anyone should be comfortable with, but I don't see why civil cases should be allowed to just flip-flop for years and years and years (I realize only one flip-flop is mentioned here, but I've seen cases where it happens multiple times).
It's like WHY EVEN BOTHER to have lower courts when what they say doesn't mean jack and will just get appealed and appealed and appealed? It just wastes time and money. It also shows that apparently judges at various levels are seemingly incompetent since someone else just overturns it. And even WHEN the Supreme Court WILL hear a case, how many of those are voted 5/4 or 4/5??? And THAT determines people or companies' fates? It's a TOTAL CROCK.
If they can't get some kind of actual consensus about something, then it should be 100% legal every time (i.e. the idea in criminal cases that if there's ANY reasonable doubt what-so-ever, then they should go free). I don't see why civil cases should be any different and I don't see how you can be found not guilty in a criminal case and then found guilty in a civil one (e.g. OJ Simpson trial). THAT is an even bigger travesty. It 100% contradicts the previous trial. That should also be considered double jeopardy since you can't be guilty in a civil case of murder and simultaneously not guilty in a criminal case by pure LOGIC alone. Either you did it or you didn't. There's no "BOTH" except in a movie with time travel paradoxes.
Wow... where do I start? Lets try the difference between criminal and civil court. In criminal court, the government is accusing someone, and they stand to face a punishment which harms their liberty in some way (their freedom or their purse usually). To make it difficult, we make it hard for the government to do that and give them a really high hurdle. In civil court, private parties accuse eachother, and they stand to just lose some money. When only money is involved, the standard doesn't have to be as high, and it varies depending on specifics.
OJ wasn't found guilty or anything in civil court, he was found liable for a death. Murder (criminal) and wrongful death (civil) are two very very different things. Wrongful death can be simply negligent (for example, you spilled some oil in your house that you didn't clean up, and then a guest slipped and fell and died.) For wrongful death, the liable person must repay someone, usually the familly, for the wrong. Murder is the highest form of homicide, it's only for someone who is really super culpable and morally reprehensible. For murder, we take away the guilty person's freedom for a long time usually. (not commenting on the OJ case specifically, he was totally guilty, we all know it). So as an example, in OJs case, the government didn't reach the hurdle to take away his freedom for doing a super morally reprehensible thing. The victim's familly did reach the lower hurdle of holding his responsible for the cost they suffered.
Appeals aren't retrials. Appeals happen when the lower court judge got it wrong. Sometimes appeals are sent back to the lower court with instructions to fix one aspect of the case. For example, a case can have many questions to answer, and only one of those questions is sent back to answer again. Once something has been decided on the merrits, it's done. Just like in criminal court, it cannot be decided again. When you see a case go back and forth up and down the appeals process many times, it usually means it was a very complex case with lots of questions dependent on eachother. If A is yes, then B? If A is no, then C? if C is yes, then D? etc. Once A is answered, and affirmed on appeal (or appeal denied), then A cannot be asked again. If A is appealed and reveres, then the court can make them go do B or C again because the answer to A changes what B and C were asking.
tl;dr: You're irritated because you don't understand what the courts do.