Several artists are known under this name:

1) A Pop punk / Emo band from the Southeast Michigan/ Northwest Ohio area. The band consists of five members: Mat Kerekes (vocals), Nick Hamm (lead guitar), Jake Duhaime (drums), Ryland Oehlers (rhythm guitar), & Eric Hamm (bass). They are currently signed to Run For Cover Records (http://facebook.com/citizentheband) (http://citizenmi.bandcamp.com/)

2) A brocore band from Denver, Colorado. Loud, fast, douchey and rather boring to say the least. (http://citizenhardcore.bandcamp.com)