I agree! On top of that, the ability to free-ride off of other's data without permission could be seen as an attempt to stiffle innovation as well. Why should I take the time to build something when (a) others can come along and use my data for free and take away my market share or (b) I can just wait a year and scrape the data off of somebody else and not do as much work.

It seems about time Craigslist re-evaluates creating an API. They have such vast amount of local data that others could use that they could easily charge for use and make some money there.