Copyrights and Sample Usage [RANT]

Why is it that you see the following notice in a lot of samples?

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
// KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
// PURPOSE.
//
// This material may not be duplicated in whole or in part, except for 
// personal use, without the express written consent of the author.

OK, exactly what would be “in part”?  How much of the source, if you were to use, constitutes a “part” of the original.  One word, a line, three lines, a whole method, a class, or a whole module? 

Why is it that someone puts some source code out there for the benefit of others, they they restrict the usage of it.  How are they supposed to monitor the usage of said source?  Are they just going to go around and accuse everyone that is doing something somewhat similar and require that they prove they didn’t use their code?

How about I rephrase the above a little:

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
// KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
// PURPOSE.  SO IF YOU USE IT, YOUR COMPLETELY ON YOUR OWN.  DON'T CONTACT
// ME AND BUG ME ABOUT WHY SOMETHING DOESN'T WORK.
//
// This material may not be duplicated in whole or in part, except for personal use,
// without the express written consent of the author.  Basically, if you want to use this code
// or any of the techniques/ideas presented here for a real project, you need to pay me; but
// keep in mind, I'm not going to offer any kind of support.  What you see is what you get.
// Also, if you've even glanced at my sample and decide to do something in any way similar
// you need to get my permission as well (and pay me).

Am I off base on this? Also what happens if say you get a sample that was written in C#. You convert the code to VB.NET.  Who owns the code?  Although C# and VB.NET have their similarities… there’s enough differences that the code has to be significantly modified in order to get working.  Just because the techniques are similar, they both use the same API’s, and the class/methods have the same names… is the code the same?  Does the original copyrighter still hold the rights?  Can the person redistributing the VB.NET version of the sample be held liable for it’s usage by the original C# sample author?

Don’t get me wrong, I don’t mind giving credit to where techniques and ideas come from and pointing out that the VB.NET version is based on the C# version; but come on, why release source code and then limit it’s usage?  If you release the source, release it!