Well actually EA did admit they screwed up in the past, but they're trying to better their lives. Unfortunately recent news about Mass Effect didn't bring them much positive attention.
Anyway, I do think that if a game has decent copy protection it will help sales, but making it too restrictive will only have the opposite effect. Still, many people would get pissed off with their failing pirated works they'll buy the legit one after all. But if you definitely want to do protection right, you should give added value to a game, like making it require a code to play online.
Copyprotection done right:
Call of Duty 4
Test Drive Unlimited (offline isn't too exciting, online it's the best racer ever)
Neverwinter Nights (CD check removed, key needed for online only ever since a 2004/2005 patch)
Copy protection done wrong:
Bioshock: Okay, I could argue like above, saying that many went out to buy it anyway, but pissing off your customers such a way really makes me wonder if it was worth it. Don't bite the hand that feeds you.