Copyright can not be applied to ideas. it can only be applied to an implementation of an idea, or a creation or an expression. Copyright is granted automatically by the simple act of creation in most of the countries. Hence a notice is not even required. Even more some copyright rights can never ever be lost and you can get them back in court pretty easy.
For example you can buy and own a painting of Michelangelo or Van Goth and you can use it to gain money by displaying it ... BUT you can never claim that you have made the painting or obscure the author's signature/notice.
If you ever do so then it is very easy to loose the painting and to pay huge retribution to the author or his family. Yes copyright is inherited and hence there is no end to it.
Patents on the other side can be put on whatever you want to. Any kind of idea no matter how fantastic or not even possible to be done today is usually granted if the claims are logical and respect some rules.
The idea is that the state gets money and if you want to pay big money for an idea in the sky that can not be implemented or enforced them "so be it".
Hence even a mouse click or the idea of a computer of any kind or the general concept of a button or a list box in a GUI CAN be patented. I have seen patent for "any device that controls the computer with thought" ...
The only good thing about patents is that they eventually expire someday while copyright never expires.
With patents you have to go to court to enforce them. And you can imagine what happens when the big time lawyers compete with "Joe the Programmer" with no big time money to spend... you surely loose unless the patent is invalid.
When a conflict appears in between two big corporations they usually exchange patents, plus or minus a certain amount of big money and they go walking.
Hence if you break a patten it does not matter that you name it "gxx" or "xxx" or "yyy". As long as the same concept is used then you are guilty.
Sometimes even the name is an issue if it is close enough to a TM and it is not a very common word but the concept behind your code / apparatus and the "method of functioning" is much more important for a patent then how you name it.
Practically you do not have the right to use an idea unless you pay.
Yes there are countries where software patents do no apply (mainly Europe) but if you have a software and somebody from US downloads it? And anyway the pressure from corporations is that all countries should accept software patents and with enough money this will be the case one day...
Also do not think that you can hide behind "closed source". When a court of law orders you to "show" the sources you must comply ...or otherwise you will spend the rest of your days in jail for contempt until you show the sources...
I have seen people that are very "smart" and "strong" in real life but when confronted with a judge that can destroy you with a signature and he/she looks into your eyes and asks if you are ready for this ... they will do whatever it takes
Basically if you want "success" and "famous" then you have to be ready to pay big amounts of money, to have the right social connections in high class business world and being a programmer is surely NOT the right location for this.
Programmers get "used" by rich, powerful and famous people ... not the other way around. So you would be better of either creating everything yourself from scratch AND avoiding patented algorithms or prepare to pay...
Of course if your target is only hobby and if you do not offend by your work the interest of a big player ... then you might (just maybe) be "spared".
