If you are angy about something and want to let folks know, you are probably not alone in your feelings. If the facts are straight and you have done your research and you are still angry, you need to get into action. Write your letter twice. First write the letter to the editor and let it sit. Take their thoughts into consideration and write the letter again.
Most online publications have email letter to the editor systems.
In fact, start a letter writing campaign of your own around this issue. It is very important that citizens participate in the journalistic process. We have more control over what is covered and how it is covered than we realize. Your letter represents many others which are not written. You need to channel your anger in a way that is productive, and letter writing is a wonderful stress management technique.