Craigslist requested that classifieds aggregator Oodle leave out its listings from search results, according to Oodle's blog (http://oodle.typepad.com/oodleblog/2005/10/wheres_craigsli.html). Oodle is a service that aggregates ads from a host of classified ad websites so consumers can search for items in one place. Oodle said only about 20 percent of its listings came from Craiglist, and without them, they have 4.5 million active classified listings.

The Oodle post said the company has gotten a "good response from the 99.9% of the other classified publishers in our index." It said it sends classifieds sites free traffic and don't compete with them by taking listings.

What is not certain is whether Craigslist has sent or will send similar requests to other aggregators. SimplyHired.com, a jobs-listings aggregator (http://www.simplyhired.com), was still serving up Craigslist job listings as of Sunday evening, and there were no posts about the Oodle-Craigslist controversy on its blog (http://blog.simplyhired.com).

This is not the first time Craigslist has asked a third-party search tool to stop its service from accessing its listings. In June, users were disappointed when Craigslist banned a tool from developer Jeff Atwood that allowed for multi-city searching of the online classifieds website (http://www.auctionbytes.com/cab/abn/y05/m06/i29/s01). Craigslist founder Craig Newmark did not respond specifically to the banning of Atwood's tool at the time, but told AuctionBytes, "We block usually because someone hits our servers really hard; and also, we've had overwhelming feedback to emphasize the local nature of our site."

The policy against aggregating listings is reminiscent of eBay's 1999 lawsuit against Bidder's Edge, an auction-listing aggregator (http://news.com.com/2100-1017-241083.html). (eBay now owns 25 percent stake of Craiglist.)

Search guru and author John Battelle first referenced the Oodle posting on his blog and promised to follow-up if he hears back from Craig Newmark about the Oodle matter (http://battellemedia.com/archives/001930.php).

Here's what Greg Sterling of The Kelsey Group has to say in a post on his blog: http://blog.kelseygroup.com/kelsey/index.php?/weblog/more/craig_vs_craig

And Danny Sullivan of SearchEngineWatch is also watching: http://blog.searchenginewatch.com/blog/051014-115749