Before the change to the copyright act, some souless bean-counter in an advertising agency could take my pictures - which had been paid for with someone else's money - and say 'Let's open a stock photography library'. They could then sell my pictures, for more than they had paid me for them to someone totally unrelated. Well, that's unfair. I refused to surrender my copyright.
Over the years I have taken many stands on behalf of the industry, starting with insisting agencies paid for film and processing - after all a plumber gets paid for his pipes and fittings! I invented devices that fitted inside cameras which placed a copyright disclaimer onto every frame I exposed - most photographers didn't understand it and just gave their stuff away.