Mostly nice folks using craigslist in my experience. Bought our RV from an ad. Always some scammers, right? That RV/car scam is several years old, and they don't have to get a "sale" to pick up plenty of info about you, email address first, then perhaps phone number etc. I have had a couple of times responding to an ad where I just didn't feel right about it. Three times I ask the same question with no response, just come look, or the location of the item changing. If it feels weird, no need to follow through, there are so many sellers to choose from.
Craigslist now has the contact info "hidden" in the reply. Several folks still spell part of their phone numbers to avoid bots. I have an out of state area code and that will increase. Just didn't want everyone I know to lose my number. Keeping the same number was just easier.
Good luck with your search, your perfect RV is just waiting to be found.