In the past, do you think anybody ever looked at the classifieds page in a newspaper and thought "this data is owned by the Times"?
In the PadMapper case, who are the losers? Renters benefit from a radically different UI and de-cluttering of daily reposts. Owners benefit from the increased traffic to their listing. Craigslist benefits because it's more of a 1-stop-shop for owners: post to craigslist (and pay them), and get some level of syndication to different services and apps. They also aren't losing out from reduced mindshare of renters: when you use PadMapper you know you're using Craigslist. It's always obvious and all links point there.