The battle between Craigslist and eBay heated up yesterday after Craigslist filed a countersuit charging the auction giant—which holds a 28.4% stake in Craigslist—with offenses ranging from unfair competition to trademark infringement, the New York Times reports. The action is in response to eBay’s lawsuit filed last month, and is being driven by eBay’s launch of its own classified listings, Kijiji.com. (More Craigslist stories.)