If you ever notice when you arrive at an airport there are signs warning of things prohibited to taking on your flight. Besides the obvious things like guns, & knives, most people wouldn't consider such hazards as camp ladens, can of spray, or lap top batteries. There are a whole list of items you have to be careful packing. Stuff like dry ice, or paint is considered hazardous material.  With more people traveling with an assortment of portable electronics sometimes a plane has hidden hazards. Case in point, there had been some incidents with fires breaking out in the cabin due to laptop computer batteries overheating. Since 1999 there had been 22 fires with more then half occurring in the last three years. As we approach the holidays more people are carrying more stuff. Passengers should be mindful of hidden hazards they might be carrying.