Codename: Kids Next Door

A TV show about an organisation of children devoted to fighting teenage and adult tyranny with 2X4 technology weapons. One of the best old-school cartoons around because of its deep and detailed worldbuilding, extensive and well-developed characters and great plotlines. The kids live in treehouses, in 'Sectors' of about five operatives, and have assigned codenames; eg. Numbuh 1, Numbuh 2, Numbuh 3, Numbuh 4, Numbuh 5, who are the main characters in the show. They fight villains such as father, the Delightful Children From Down The Lane, Knightbrace, and Count Spankulot, as well as many others.
Though this show has been off the air for a number of years, it has maintained a fanatical following, who I am proud to be part of.