It has a funny name but not too many people in some Chicago neighborhoods are laughing about huge piles of Pet Coke they say have left their homes and yards filled with soot, and could be a potential health hazard. Pet Coke is a by-product of the oil refinery process and is expected to become more plentiful as refineries process more heavy crude oil. Left uncovered, a strong wind can push Pet Coke dust into the air, waterways and nearby neighborhoods. The Illinois Attorney General and Chicago residents have filed lawsuits against the facility storing it in open air, which belongs to a subsidiary of the controversial Koch Brothers. They say the company should find a better way to store pet coke before its shipped elsewhere.