Citations!
If we don't use citations we are not giving credit where credit is due.

As far as plagiarism in the professional setting, this happens more than people realize. When a supervisor takes credit for what a person under them does, this is plagiarism. This is a situation that goes on a lot where I work. A co-worker and I do attempt to give the proper credit where it is deserved, and our superior, whom is over our supervisor is aware of the situation. This is what we have done to make sure that the appropriate people know who is responsible for a particular idea, or the work that has been done.
When plagiarism happens, it is important to notify either a supervisor, instructor of official in charge who it is that actually deserves the credit.

Sometimes it does not pay to get mad.