I'm confused then because according to founder Greg Kidd 3taps does not get its data by scraping Craigslist:
"...We didn't get the data from them anyways. We're finding it from other sources which have already indexed it like Google, like Bing, like other search engines that are out there."
If you read the fine print (which is in various documents linked to on 3Taps' website), you find that it's not quite as simple as that. 3Taps started out getting the data from Google; but when Craigslist found out what they were doing, they restricted Google's access in a way that made it necessary for 3Taps to scrape Craigslist's site directly.
It's notable that, in these documents (which are written by 3Taps), the fact that Craigslist sent them a C&D letter is never mentioned. So it's not clear where, exactly, in the process the C&D letter came in.
"...We didn't get the data from them anyways. We're finding it from other sources which have already indexed it like Google, like Bing, like other search engines that are out there."
http://www.youtube.com/watch?v=6Rf6JrSYZ4U#t=27m32s