Yes. The ability for the average citizen to gather, analyze and publish their own news is paramount in ensuring the main stream media does their diligence on their own news stories. I would imagine the major news network executives would not want to see their headlining story proven wrong by the average citizen. I think that overall, the positive impact of citizen journalism is keeping the main stream media honest.
Web 2.0 is the same as social media. Social media such as Facebook and Twitter are Web 2.0. Social media is important to citizen journalism because of the social beings relating to each other. The more that the social beings relate, the more relevancy for the use of Web 2.0.
In May 2016, a tweet was spread and seen worldwide, claiming that Americans were immune to the Zika virus, hence not needing any type of injections or immunizations preventing against this disease. As a result, many opted not to take the prevention against this disease. Ladies and gentlemen, today we can see that with the spread of citizen journalism through the use of media, it gives society an unreliable source of information, info that many may choose to rely on to make heavy decisions, decisions that could come to harm you and our society.