End all fraud. The online version of this is, Spam, Phishing, Spyware, identity theft, etc. Offline: con artists, political bribery, tax evasion, ponzi schemes. I don't believe eliminating all crime is possible, as I can always whack my neighbor over the head with a stick and steal his wallet, but alot of crimes are only possible because the victim has a lack of good information. This is fraud. Eliminate or drastical…
Crime helps point out design flaws (case in point: Email) and can be therefore be thought as a force fostering or even forcing innovation. Not defending crime, just pointing out that eliminationg crime is not a pure win-win situation.
Disease forces innovation as well. The eradication of polio in much of the world is not a lost chance for innovation--it is a success story.