Never, under any circumstances, take someone else’s work and call it your own.
If you take copy, video, audio, a photo, or information from another source, attribute it.
If you take someone else’s material and use it without attribution, you are guilty of one of the most serious breaches of Journalistic ethics, and if you’re caught, you will likely face serious disciplinary measures up to and including termination of employment, not to mention possible legal action.
Stealing someone else’s work is a breach of integrity and credibility, two of the most important attributes of a Journalist.
Some people believe that with the proliferation of information on the internet, any and all content is up for grabs. Some people believe that in the rapidly evolving news world, with bloggers and Tweeters operating under a different set of standards than professional reporters, that the “old rules” don’t apply any more. Nothing could be farther from the truth.
The Society of Professional Journalists has a very clear and easy to understand statement regarding plagiarism you can find here.
The Poynter Institute has a flowchart to help determine and define plagiarism here.