donquixote, I have explained to the best of my knowledge. If you want to know more, you must consult a lawyer. Someone specialized in intellectual property law. Theory is one thing - practice is another. That real artists steal from other artists is very uncommon, it is really not a problem, It is photographs that is the problem.

Sense of proportions is the most important thing in life. –Winston Churchill.

In juridical terms there is a concept called "natural law", = what people thinks is right and wrong. The legislative powers strive (ideally) so that written law and natural law coincidence. All photographers like to think of themselves as artists. And the modern law tend to agree with them. But in practice the "natural law" does not agree.  If all copyright infringements of photographs not registered and with no commercial value should be taken to court they would have nothing else to do for the next 1000 years or so. One simply cannot sue for $10. In addition there are million of millions of free photographs on dozens of sites on internet. Demand and supply rules.