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 drastically reduce all fraud.