Releasing a unique hack mostly using other people's stuff

[Erwin]

Originally Posted by tamarian

You are wrong in your interpretation , and I also disclaim that I am not a lwayer (IANAL)

This has exactly to do with AT&T not having any copyright notices on their source code. And AT&T distributing the source code to universities and having it published in educational books etc., that rendered it public domain.

AT&T had to add the copyright notice, and Berkly had to do likewise, but they earned the right to use it, provided they maintain the notice. But the key point was that AT&T failed in asserting their copyrights, and preventing further release of BSD, and the main point was due to distributing the code without a copyright notice. Note that even public domain source code can have a copyright notice on it.

There are other angles in that case, but since then, everyone knew the value of indicating what copyrights and license they whish to claim on that code and clearly refrence it in the source code, to avoid having it considered public domain.

That's why even if you think you're protected, include the copyrights on the headers just in case, and don't take anything for granted, why risk it..

Well, I am a lawyer.

From what I understand, AT&T lost copyright over the code by distributing it widely, effectively making it open source. They implied they were waiving their rights to it. That's different to saying that source code with no copyright notice is automatically open source.

Similarly, if I make a script, and send copies to everyone without making it clear that it is not public domain, my actions imply that I want it to be public domain. However, if I make a script and only upload it to vBulletin.org which only licensed vBulletin owners can access, that hardly means I want my script to be public domain.

See the difference?

Disclaimer: Though I am a lawyer, the above is not formal legal advice.