There is an issue within an issue that needs to be distinguished.
The lay person (most of us) will understandably have a general common-sense based belief that "to copy someone else who has a patent on a device is clearly wrong." But the law puts some distinctions on this general maxim which makes exceptions to this general case. The Apple v. Samsung suit is a prime example of this distinction.
COPYING vs. PATENT INFRINGEMENT
In general, the U.S. Patents and Trademarks Office grants a patent to a party who has successfully followed their procedures for applying for a patent in order to safeguard a clearly defined piece of intellectual property from being used by others who do not share or own the intellectual property. Among other reasons, this is done to encourage the invention and development of new ideas - otherwise (as the argument goes), if everyone could instantly take and use (with no negative consequences) what it took another party years of money and hard work to develop, there would NOT be a lot motivation in the first place to inspire anyone to "build a better mousetrap." Think how you might feel if the new car you just bought (by working hard and saving), could be legally taken by anyone else when you weren't driving it and freely used for their own benefit, or any homework you did for school (where you stayed up late the night before to finish and do it correctly for a major grade) could then be freely copied and shared without your permission by anyone the next morning to turn in for their own grade. Obviously, this would not be agreeable.
By acting as though a novel idea or approach (that can be clearly defined as uniquely worthy in the Patent Office application process) is a type of property that can be owned and controlled (even though it is intrinsic and not material), the law seeks a means to provide protection and ownership rights to those who put all of the hard work and development into an idea and then must bring it out into the open to market it (thereby exposing their idea to potential competitors who can see the end result of what was done).
Alright, having said all of this, let's go back to the idea that "to copy someone else who has a patent on a device is clearly wrong" and see what the law deems important. A better way of saying this would be to state "It is wrong for one party to copy a part of a device made by another party that has a patent on that particular part of the device, but it is not wrong to copy all of the rest of that device which has no patents on it."
This means that if (to put it simply) an item has 100 parts, all new and never seen before, but only one of those parts has a patent on it and all the other parts have no patent protection, then it is perfectly alright to copy the 99 parts to a "T", but not that 100th part with a patent. On that one part, you must either build your device without it, or if you find the utility of the patented part indispensable, you must find some other way of doing it that does not encroach on the patent of the first party.
Obviously, given the extreme case offered, it would be possible for the two items, sharing 99 out of 100 parts, to appear identical and therefore one would seem to be a copy of the other, but in terms of patent law, the maker of the first item would have no case against the copy cat as long as the patentable part was not copied.
TRADE-DRESS
There is also the distinction of "trade-dress" or (simply put) how something appears at the point of purchase as a matter of potential confusion to the consumer. To continue with our example, although nothing would be wrong with copying 99 parts out of 100 to manufacture your product, you cannot copy the 99 unprotected parts in such a way that would lead an ordinary buyer into thinking your 99 part copy was the 100 part original. An extreme example of this (for illustration purposes) would be to make a legitimate 99 part copy that did not violate the 100th part patent on the original, but then market or package your product in such a way that it suggested to the buyer that they were purchasing the 100 part original. So, even though your manufacturing process did not violate the patents of the original, you would still be in violation if you created confusion in the mind of a consumer where the layperson would look at the two products, side by side, in their own packages and, because they were so similar, might become confused as to which one was which.
Sometimes a product will be granted a patent (after all the Patent Office is not perfect) which simply cannot (or should not) be attempted any other way, and this is considered onerous to competition and will be disallowed when challenged. An extreme example again would be where someone first came out with a round wheel for use on a transport conveyance (like a chariot or cart), and the Patent Office of that time sees this and says "Yes - this is unique - we'll grant a patent). The round wheel hits the road and everyone who sees it wants one, and the blacksmith who came up with it is swamped with orders. Competitors who want to also enter the wheel market will see that it is patented and promptly set about trying different designs that are not round, and will quickly come to the conclusion that any wheel, to be minimally useful, has to be round to be practical. They may then challenge the round wheel patent in court, saying that a patent was given to a design that is actually "obvious" and cannot be accomplished any other way.
PRIOR ART
Or, in the above example, even if the design cannot be deemed "obvious", a party challenging the patent granted to another may introduce evidence which shows that, although the idea of a round wheel may be unique in our culture, it has been used for hundreds of years in Europe (or another culture) and is therefore a simple re-introduction of prior art made to look as if it is a new patentable idea (irrespective of the intent of the patent holder who applied earlier for the round wheel patent). As such, the patent will be rescinded.
APPLE v. SAMSUNG
In the Apple vs. Samsung case, there seem to be several issues overlaying each other (which lawyers typically do to protect their own client's interests). I will make simple parodies (of the actual more complex legal issues) from my examples above to demonstrate.
1. APPLE: We are claiming that of the 100 parts we use to make our devices, 20 of them are patented, and Samsung's product(s) have wrongly copied 15 of the 20 protected and patented parts, and that Samsung must stop copying those 15 patented parts when they make their product(s).
SAMSUNG: We are allowed to legally copy the 80 parts out of the 100 parts you use to make your products. As an example, you have a basic rectangle with rounded corners and you don't like us to make our product like that, but we are legally allowed to because the rounded rectangle is prior art and besides, the most practical and obvious way to make a tablet.
APPLE: You are not responding to what we are saying - you are getting away from the charge of wrongly copying the 20 parts we have a patent on, and instead you are concentrating on the rectangular shape of the device, which is one of the 80 parts we don't have patented.
SAMSUNG: What are you talking about? You yourself have gone to great lengths to show that our rectangular product looks like your rectangular product! Now you are saying that the overall look of the device does not matter?
APPLE: When both products are dark (turned off), the similarity does not matter. Granted, we are not thrilled that they look identical and we have used a cheap trick in court to sway jurors on that angle in a European case, but there was a different set of trade dress issues on the table there that are not the major thrust of this case. But the "rectangle with rounded corners" argument you are advancing is disingenuous because it distracts the jury from the real issue at hand - your violation of 20 patented parts.
SAMSUNG: But some of those 20 parts you are claiming to have a patent on is clearly what you see when you compare the two rectangular products side by side. Now you are saying that the similar look of the two rectangular products doesn't matter?
APPLE: NO - what we are saying is the the single aspect of rectangular with rounded corners - what you see when the displays are dark and compared side by side - does not matter - despite the vigor with which you attempt to distract the jury. What we are saying is that once the displays are switched on, that you are using 5 of the 20 patented parts (that are protected) in your own design and that is stealing from us.
SAMSUNG: But the use of icons against a background picture has been used by other (prior art), and besides, even if we did copy that, it is the only practical way to do it (obvious design).
APPLE: But again, you are using a general case to make your point and we are talking about the 20 items we have patents on - 15 of which you have illegally copied. Yes, icons are an example of "prior art" and may even be deemed "obvious" - but you have attempted to steal the overall artful look of our screen when switched on (trade-dress) - so that consumers who are used to the same product being sold under different names (e.g., Chevy and GMC pick-ups) may think that your products and our are the same thing - when they are not. You have used our identical icons in an outright rip-off of our icon collection art designs and have included those in your product even though you don't even have the app that links to the icon. That alone goes to prove that you are outright stealing, and not just copying what we do.
SAMSUNG: But you didn't copyright the artwork for those icons so we can freely copy them.
APPLE: WE didn't have to because it is part of the trade-dress of our overall presentation, and besides - the copyright is conferred as a matter of original art even if we didn't register it with the U.S. Copyright Office.
and so it goes... all of which (if it took you a few moments to get through all of this) must be exhausting to a jury.
My apologies to the "legal eagles" among us for any faux pais (or language difficulty there might unintentionally be). My only intention was not to pose as an expert, but (as one who has more than a passing interest in this case) to share my own views.
I thank you in advance for your kind consideration.