The web seems to be converging on several companies, like Facebook and Google, which are becoming more powerful and increasingly unrivaled. Yet, even these companies can't afford to close off everyone else and have a very healthy ecosystem of companies and services developed around them. Still, there are those that are more reluctant to sharing their data and Craigslist is again proving to be one of these companies. The site didn't really like a project, called Flippity, which took listings and plotted them on a map, so it decided to block it along with everyone else who was using Yahoo Pipes to access the data.

Developer Romy Maxwell, one of the people behind Flippity, had several email exchanges with founder Craig Newmark, the Craig in Craigslist, to get his opinion on the way the project used and accessed the data. Initially, Newmark gave the project the thumbs up and it looked like everything was in the clear. He replied to one of the developer's emails “as a rule of thumb, okay to use RSS feeds for noncommercial purposes,” which is what Flippity did.

A few days ago, the developer sent Newmark a link to the project which was at that moment in alpha stage. He didn't receive any reply to that email, like he did for all the others, instead Craigslist essentially blocked the project from pulling the data by cutting off access to any app that used Yahoo Pipes, without any official explanation at this point. Maxwell says that he could have circumvented the blocking, but that it’s now worth the effort when other services are a lot more welcoming to third-party apps.

“With the likes of eBay and Oodle not only providing open APIs but encouraging and rewarding developers, spending my time wrestling with Craigslist is just plain stupid and exhausting,” he wrote. “By the way, it's not too hard to defeat any technical measure Craigslist can put up...There's very little Craigslist would be able to do to counter. However, it's just not worth my time. If Craigslist wants to keep its doors shut to the world, so be it.”