Who can I report to about someone who has a Yahoo address and Instant Messenger about a scam?

Brenda L asked: He is online right now and very brazen. He stole over $6000 from me after befriending me through a Christian website. He must be stopped. Can someone please help me catch him. He even displays a picture with his Yahoo messenger

what do i go to report a scam?

J W asked: i receive a cashier check i think it’s fake. i did some resource online and i notice alot of what they was saying online fit what the person is saying to me. i want to know where do i go to see if this is a scam or not?