Yes. What was once a relatively easy way to list services and so on has become a haven for scams and predators. As a tutor I listed my services and only got scam mail in answer to it. People claiming that they have custody and wanted to secure my services, but first I had to cash their international check and take my pay off the top. Or please click here for us to see your credit rating.. etc.
It’s not worth the problems anymore. Even responding to what appears to be legitimate job offers has become a SCAM haven. Though some have been real, but out of 120 responses only 1 was legit. Craigslist has gone downhill and I am not surprised if it eventually folds. Someone should come up with a better type of craigslisting service where you can really be safe. No anonymous replies would certainly help that way we can see who we are dealing with and can report it more efficiently. I still like to go through the ads, and I still do list, but I keep my real email open so people know I am legit.

I have bought and sold many things on Craigslist. Unfortunately, you can't trust everyone. So, to stay safe here are a few suggestions in case you decide to enter the marketplace.

1. Never go to meet someone from Craigslist alone. Take someone with you and let others know where you're going.
2. Never let anyone in your home. If you are selling an item, consider meeting at a central location such as a mall or other busy, people filled area.
3. Just like any other website, if it's too good to be true, it usually is. No one is going to sell an iPhone for $50 unless there's a catch, and there's always a catch.
4. Never send money, always complete transactions in person.

Hopefully you'll have better luck than your friend..

You certainly aren't the only person that feels this way. The Craigslist posting guidelines (links in the references) are well intentioned, but they just don't stop the deluge of spam and scam postings.
FULL DISCLOSURE: I'm building a service that tries to address these same kinds of concerns, because I feel the same way.

I think it is very important to be selective in who you decide to let into your home, never invite a stranger over while you are on your own... and keep your valuables tucked away. If you decide to buy something from craigslist make sure that you can view the item and that you know enough about it to determine its value. If you do not have enough knowledge about the item (ie. electronics) then it will be better to buy from a trusted source. If you have to meet to verify an item then do so in a public and busy location whenever possible. There are some crazy people out there and it pays to be extra careful.