Craigslist is often held up as an example of a company "doing it right", but what is never mentioned in these posts is that a large portion of their revenue comes from facilitating scams. Around 25% of rooms/apartments I contact are scams, and Craigslist has so far done nothing to prevent these. A common scam is to take pictures from a real estate site of a house that recently sold and advertise it as for rent, but they don't even let you say "I live at this house and do not want to rent it, don't let anyone post it".