Carlos is right in a way if you didn't want people to steal your source code you should have kept it closely guarded or on the top of your source code you could have write a comment saying that you authorise people to use it but they should say that it is yours well you choose for yourself but that's just an example,
This is actually written by me. I wrote the development kit gem, and its purpose is to help everyone who uses UDK. There is little reason to actively with hold Unrealscript code, besides Epic is giving you all of theirs.
Source code like the one posted on the UDN solves things which can be done in many ways. There is always a huge possibility that I may have just written it in way similar to yours.