Ernest N. Wilcox Jr. a écrit :
I will not enter into the argument that it is not illegal untill the patent holder comes after you.
Strictly speaking, it is not illegal until the patent holder decides to demand compensation, the user refuses to pay, and a court upholds the patent holders (claimed) civil right. Most patents are NOT valid. Patents are issued on the basis of not conflicting with other patents, not on the basis of validity, which would include among other factors, prior art (originality).
Remember that Microsoft has a patent on certain essential elements of a spreadsheet - obtained long after the first spreadsheet. (Which wasn't produced by Microsoft.)
And patent holders could decide that it is not in their interest to demande compensation. Mpeg is an excellent example. By pushing free software to not use mpeg, they would be discouraging the use of those standards, which would lead to more use of alternatives, even among users that (directly or indirectly) pay royalties for the use of mpeg.
So yes, it is definitely NOT illegal, in itself, to use software subject to patent claims without paying royalties, in those countries with software patents.
To my way of thinking, that feels very similar to saying that stealing is not a crime untill you get caught.
Before accusing someone of stealing, one has to ensure that someone else has ownership rights (legitimate patent), and is willing to exercise them (and demand royalties). Even legitimate patent holders are permitted to allow free usage, just as you are free to give away anything you own.
