They're changing it to have legal grounds to fend off sites like Padmapper. If they have the exclusive license and another site copies the add and gussies up the display, they have legal grounds to go after the infringing site now. Prior to the explicit issuance of an exclusive license, lawyers for alternative services could make a compelling argument that Craigslist did not assert any license to the content and therefore couldn't legally prevent them from offering a service on top of Craigslist. Adding the copyright license closes that loophole. Now, whether or not an exclusive copyright license is the best way to go is a different question.
Standard IANAL disclaimer.
Edit: replaced copyright with license. Low caffeine morning.
It should also mean though that cross-posting to other sites like Kijiji (very common) could result in having take-down notices sent for your ad (- since it's an exclusive license you're granting them). [IANAL]
You're right. That's where the exclusive vs. non-exclusive copyright license comes into play. I also wonder what this will do to the rentals market. For instance, local realty company lists all their properties on their website and posts them on Craigslist to increase traction. Craigslist now sends the realty company a takedown notice, for the realtor's website listing, since they copied the listing onto CL. Depending on the level of enforcement CL pursues, this could have the effect of cooling professional usage of CL--especially by organizations that have to run things by legal first.
The information that is used to build the ad remains open to be used wherever and whenever the poster wants. I believe this storm is caused by third parties leeching off their ads and not users posting the ad in multiple places. Let's not get too dramatic about it.
Correct, the information remains open--however, how many people are going to go about writing a new ad for each site they post on and make sure it's different enough to avoid triggering someone else's license protection? Reading real estate ads in the area, both on realty websites and Craigslist, they look almost identical.
"BRAND NEW CONDO 1BA 1Br wood floors!!!! sends us an email. $1200/mo!!"
If you take that same ad and post it on Craigslist and another ad service, the license with Craigslist gives them exclusive rights to the ad--if I'm reading this right it means they can then tell the 2nd ad service to take the content down since CL has the exclusive license. I'm not saying CL will do this, just that having that kind of license up front opens the door to such a scenario.
Craigslist is not asserting copyright, rather it is asserting that it is the exclusive licensee of the poster's copyright and wants to go after e.g. Padmapper on behalf of the poster.
Standard IANAL disclaimer.
Edit: replaced copyright with license. Low caffeine morning.