I was trying to sell a couple items on craigslist and was contacted by some people. They were a bit suspicious (giving me extra money and telling me to transfer the excess via moneygram to their shipper) and then i read on craigslist that if they ask for moneygram, its a scam. I've forwarded their emails to the appropriate places, but they are still in touch with me asking what is going on and what i am doing with the checks they sent (no, i'm not going to try cashing them). What should i do now?

P.S. Does anybody want a video card or external CD burner?