In 1980, Stallman and some other hackers at the AI Lab were not given the software's source code for the Xerox 9700 laser printer (code-named Dover), the industry's first. Stallman had modified the software on an older printer (the XGP, Xerographic Printer), so it electronically messaged a user when the person's job was printed, and would message all logged-in users when a printer was jammed. Not being able to add this feature to the Dover printer was a major inconvenience, as the printer was on a different floor from most of the users. This one experience convinced Stallman of the ethical need to require free software. At that time, it became clear that he wanted people to discard proprietary software.[8]
http://en.wikipedia.org/wiki/Richard_Stallman 
I just mean, or I understand it so that the power of open source is that when you buy some software you can do with it whatever you want (so far some ethical norm allows it).
That when for example Microsoft goes bankrupt (I can dream or ... ?

) that your product goes down too because there is no support for the OS you using anymore. There is no kind of this danger with open source.
But for me this ethical norms are, that you should not take some component (lets say something like friendly URL ...) and you remove the adverting from it, and trying to "sell" it to the community as some kind of "development". To be honest, I use this component on several pages and I had never removed this part of code. I think, that to leave this, or to pay for the author's acceptance to remove this part of code, is a good idea to support the author. And I think that this what this "developer" has done, is not fair.
So, if I write a good software and will sell it, probably someone will buy this component, modify it a bit and will give MY work free as his own, and I lose my possibility to make money.
Is it really so evil to make money with open source ?