I have 2 questions for you:
1. What kind of license did you get from CL?
2. CL does not even have an API, how did you scrape the data?
2. You are right, craigslist doesn't have an API, so whether you are licensed or not, you have the same tools at your disposal. We did typical HTML scraping, but our amazing Dev team did some really smart tweaks to present the data in a beautiful way.
Are you doing the scraping server side or client side (inside the app)?