[kacir]

Originally Posted by GeoffC

but to my way of thinking you haven't explained how to stop someone making copies/adjusting and calling it their own.

Programmers can recognize their own program when they see it, even when it is a little bit adjusted, modified and with slightly different user interface.
Sometimes it is very surprising that author can identify his own work, even when it is heavily disguised.
You might remember the Sony Rootkit Fiasco.
See http://en.wikipedia.org/wiki/Sony_rootkit

Originally Posted by Wikipedia article

Additionally, further investigation revealed that Sony had created its copyright protection software, in part, using LAME code written by Jon Lech Johansen, violating the GNU General Public License

The above described situation was extremely ironic, because Sony distributed a program (rootkit) that was supposed to protect their ... aehm ... "Intellectual Property", and used stolen code. AND they stole it from Jon Lech Johansen -- also called DVD Jon -- the guy that was the very first programmer to defeat the principal DRM that protects the DVD disks - the CSS system.

When thinking about the GPL license you have to divide the licensees to three categories.

1. Users. They can do pretty much anything, without any "thou shall" clauses.
2. Programmers using the code for their own need (or even the need of the company they work for)
3. Programmers that want to use the code AND distribute the result.

If you want to use a piece of GPL licensed code in your own work, for your own use (that is without distribution), you can do that. It is expressly allowed. The "thou must" clauses kick in ONLY if you distribute the resulting program.

Of course, many people think that they can use a piece of code somebody else wrote and published under GPL license. The Media Sentry programmers that programmed the Sony Rootkit software obviously thought so ;-). If the piece of code is small enough and insignificant enough, you can get away with that, but as the above example shows, you can get caught once your program becomes popular enough or interesting enough for somebody knowledgeable to have a look at it. Even if you distribute only compiled binary.

Originally Posted by GeoffC

Regarding the example about uploading to modileread.com I am not sure what your point is.

One of the posters asked why bother with a license if anybody can pretty much do anything with the file anyway. I pointed out that there are situations where you need to know what the license is.