The housing market morass has created a new class of real estate investors: the unintentional landlords.

Bartering, especially of homes, has found a new, global life on the Internet.

Microsoft is closing Windows Live Expo, the classified advertising Web site that was initially seen as a potential competitor to Craigslist.

The online classifieds company filed a countersuit against minority owner eBay, accusing it of unfair competition, false advertising, trademark infringement and diluting the value of the Craigslist trademark.

In the face of the expansion of the classified ads Web site Craigslist, its founder, Craig Newman, is capitalizing on his success to promote causes he holds dear.

In a statement, eBay said that in January, Craigslist executives took actions that “unfairly diluted eBay’s economic interest” in the company.

EBay filed a lawsuit in the state of Delaware against Craigslist, alleging that two directors took actions that unfairly diluted eBay’s economic interest in the company.