I got into a conversation with some people yesterday about how copyright works. As a software developer (and therefore someone who creates copyrighted content), I take intellectual property very seriously. It's my livelihood after all, and so I'm a bit sensitive as to what others can do with my work (and how I use the work of others).
It's amazing some of the level of misconception I encountered.
For example, someone said that if you change an image slightly then the copyright no longer applies and you can freely redistribute it. Like changing a few pixels, or the colors, or giving it rounded corners...
It's called a derivative work. This is one of the most common misconceptions, and it's thoroughly documented on the Internet (here's just a small sampling):
Myth 13 - http://users.goldengate.net/~kbrady/copyright.html
Bullet point 6 - http://www.sideroad.com/Legal_Advice/copyright-fair-use.html
Bear in mind that none of the examples above mention computer software. While they certainly apply to source code, most of the examples in the articles above refer to things like art and literature.
For those of you fellow software developers, I would encourage you to read about copyright and learn about how licensing works. Not just so you know what others can do with your work, but so you can make intelligent decisions about under what terms you can use the work of others. Especially with the proliferation of open source and the varying licenses, you will likely be prompted with questions like, "This library is under a modified BSD license - can we use it in our product? What implications/consequences would it have?"
[disclaimer - I realize that in fact I am not the copyright holder for the vast majority of the software I write, as it's almost all legally considered "work for hire"]