answered this question "the # licence does not allow closing the source code after editing it, what if a programmer steals a source code from an open source program and edits it and makes it proprietary, how can the orginal developer know, that someone # the source code ? I mean he closed the source, so nobody can see it" with: well, there are different ways to find out: 1. same # 2. if it will be compiled: analyzing # of the compiled code (there will be parts which will be similar)