I am helping a consultant debug a program he grabbed off of the internet. It is released under the GPL and seems to be really great. So I open up the code and notice... hmm... all of the copyright information has been removed frm the application. He is putting it back in, but it is a crappy thing to do. The guy knew better and I don't understand why you would remove copyright information - aside from being unethical, he is a consultant and not being paid to develop an original piece of code. He is being paid to do a job.
Sheesh, someone does all the work for you - the least you could do is give that person some credit.