The interception of packages that contained chemical explosives last week has prompted the U.S. to increase air cargo screening. The packages are believed to have originated in Yemen. They were sent on United Parcel Service and FedEx cargo planes and were bound for a synagogue and a Jewish community center in Chicago. The Department of Homeland Security has responded with an "unpredictable mix" of security, including explosives detectors, additional pat downs, and bomb-sniffing dogs. Meanwhile, Rep. Ed Markey, D-Mass., said he will introduce legislation aimed at making the U.S. less reliant on other countries for cargo screening and require more intensive screening of all cargo on cargo planes.