What if i want to replay the game? (Score 1)

There's something I dont get: - A 2nd hand sold game shouldnt be able be played till the end (or whatever), so... - The key must be only used one time to prevent this, so... - What if I want to play the game again? Should I pay for the DLC? Should I take the trouble to contact the EA to prove I am the "first only original 110% legitimate buyer" of their game? This is simply ridiculous!!