Scam artists swindle people with fake checks

Fake checks are apparently the largest scam in the US today. This is how it works essentially. A crook sends you a large check for one of various reasons: like you won a lottery or sweepstakes, or your grant application was approved, or you inherited money from Nigeria. In all cases, they want you to send them some money upfront using a check or Western Union.
If you are greedy, you will get suckered in.