Yes, someone from Craigslist offered me a job with a company they did not even represent. I contacted the company directly and this is how I found out it was a rip off.. It was a total scam so watch out for this.
Also bought a camera from ebay once (long time ago) and the person did not deliver.
Scam artists are rampant, especially on the internet so be very careful. It seems that if it seems too good to be true, it usually isn't!