Citizen journalism has evolved in two waves - the first with Indymedia and open publishing platforms, and the second with social media. While early citizen journalism was dismissed as amateur, social media has normalized habitual acts of citizen news sharing and commentary. Now, small contributions from many citizens can have a big impact through collective curation on social platforms. Both journalists and society are adjusting to this new media ecology, where news flows occur across multiple overlapping publics rather than a single public sphere. More research is still needed to understand the impacts on democracy.