Including, but not limited to the realm of journalism, conflicts of interest are often thought of in a negative light, typically for good reason. If a reporter who openly identifies as either a strict Republican or Democrat is assigned to cover the presidential debates, it will be hard for him or her to shed an unbiased light on the event. Similarly, if a reporter was a part of a group home years ago and is covering a story about that group home, there is a conflict of interest here.
Just the other day, a tech journalist was fired when editors found out he also worked for Apple. This was a clear conflict of interest, as the tech journalist frequently had to cover Apple as a part of his duties, and he didn't inform anyone of his new employment with the company. This brings up the transparency code for ethical journalism.
Conflicts of interest bring up ethical dilemmas for journalists. Bias is very difficult to overcome, even to seasoned professionals, and the unfortunate truth is that a large percentage of Americans are so heavily influenced by the media that they may not recognize bias, and instead take articles to be completely factual, giving them the entire picture.