Craigslist Blocks Yahoo Pipes After Dev Shows Craig His New Mashup

Developers take note: if you’ve got a mashup built off of Craigslist’s data, don’t even think about showing it to anyone who works there. At least, that’s the lesson learned by developer Romy Maxwell, who says that Craigslist has blocked both his mashup and every single project built on Yahoo Pipes a few days after a friendly Email exchange he had with Craigslist founder Craig Newmark.

Maxwell is one of the developers behind a new mashup called Flippity, which lets you plot Craigslist listings on a map. In a blog post, Maxwell writes that he had been having an Email exchange with Newmark over the last few weeks, during which Maxwell asked if the techniques employed by his project would be acceptable under Craigslist’s restrictive Terms of Use.

Newmark replied that “as a rule of thumb, [it’s] okay to use RSS feeds for noncommercial purposes.” Since the project used RSS feeds and was non-commercial, that seemed to indicate that the project would be OK. Maxwell followed up by asking if he was allowed to ask for donations on the site, which Newmark said he would look into. A couple weeks later, Maxwell sent Newmark a link to a working alpha version of Flippity. Newmark went silent, Craigslist pulled the plug on Flippity and every other Yahoo Pipes project soon thereafter. From Maxwell’s blog:

I couldn’t believe my eyes when I saw what Craigslist had done. They literally added a check for “” in the referrer header of any HTTP request, which was then redirected to the home page. In essence, they blocked them. Really, Craig ? This is your response ?

To be clear, Maxwell says that his post isn’t meant to be an attack on Newmark himself. Newmark actually CC’d a customer service representative on a couple of messages during the exchange, so it’s possible that they were the ones who ultimately decided to shut down Flippity and all of Yahoo Pipes.

Maxwell writes in his blog that he and another developer have been building the mashup for 2 months. The goal was to build something that would plot Craigslist listings on a map, offering an easy way to see what goods are being sold in your proximity. There’s already a great mashup called PadMapper that does this for housing, but Flippity was supposed to work for any Craigslist listing. For details on how the mashup worked, check out this post.

Of course, this isn’t really anything new for Craigslist. The site has previously shut down mashups using its data many times before. But they have permitted some sites, like Housingmaps, to tap into Craigslist data for years. And it seems strange that they would ban all Yahoo Pipes apps in response to this.

Maxwell says that this doesn’t mark the end of Flippity: the site will adapt to use another source of data, like eBay or Oodle.

We’ve reached out to Craigslist for comment and will update if we hear back.