You're right Wyrd. I have had some of my works ripped off. I am currently having a few international corporations rip off some portions of my US patent. It is very uncomfortable and my respect for those individuals and corporations is very low. You as a programmer take a lot of pride and ownership in your work as I do as an engineer and artist. For me I would rather spend my efforts developing a better mousetrap for my machines or a better digital drawing. For you, I imagine a better understanding and ability in computer science or engineeering, I don't know your area of speciality. I guess it's an individual matter of we consider important to ourselves.
But, having agreed with Wyrd and understanding what can happen if you do "borrow" someone elses ideas or programs or patented inventions, and the lack of personal development that this does foster, if you really need their program please notify them first and give them credit in your program for their hard work.