The users are also within their rights to request that Craigslist share that information with third parties via an api, or by scraping for that matter.
The point is that Craigslist is not the only side in the transaction and should not be presumed to be able to set the terms on their own.
when you submit your information to craigslist you agree to their tos. If you don't accept you don't have to submit your information to them. Once the information is in their database theres now two sets of data. Yours that exists on your hdd or your head and craigslist copy of the data that you submitted to them. You are free to do what you want with your copy of the data, submit it to other sites, allow other people to somehow scrape it... but craigslist copy of your data, they can now do what they want with it.
