Re: For a contrasting view...
"You can thank these FOSS loons in trying to get stupid patents chalked off "
And those FOSS loons actually USE copyright to prevent IP theft.
GPL being a classic example - you can use GPL stuff, you can sell it, BUT you MUST provide the source code and if you modify the original, you don't get to change the copyright and hide the origins whilst making a fortune out of it.
For those who don't mind there's BSD licensing - but bear in mind that a lot of people (like me) switched to GPL because we were tired of our work being stolen and used unattributed. It's particularly galling when you get demands to "fix" something written 20 years ago that a vendor has subsumed into a product put out under "closed source" monikers and has been making $$$ out of, with no expectation of being paid to do so.
Anecdotally: One company told me that using my stuff saved them US$83million in one 6 month period the late 1990s - I suggested they toss something my way as thanks because my equipment was falling apart, but their accountants were having none of that. It's a regular story.