Where before two communities on different sides of the US-Canadian border functioned as one, 21st century security concerns have created a divide marked by sensors and cameras.<br /><br />The centuries-old border community of Derby Line in the United States and Stanstead in Canada still features a public library intentionally built to straddle the two nations' border, but locals say the two sides are spending less time together.<br /><br />With the border cutting right through town, residents now have to worry about border patrol agents responding if they cross their backyard fence or turn down the wrong street.<br /><br />Al Jazeera's Scott Heidler reports from Derby Line.
