Yikes. When you're talking about this many of any product, you know the issue's got to be pretty serious. I think using the phrase "cathing fire" definitely qualifies...

"HP will recall about 679,000 digital cameras worldwide to fix an issue that causes the battery pack to overheat when connected to a docking station or AC adapter, the U.S. Consumer Product Safety Commission said Tuesday. One report has been received of an HP camera catching fire, however no injuries have occurred."