Don't plagiarize. Seriously.
I would rather have you not do your homework at all then hand in something you didn't write.
And honestly? If you are going to plagiarize at least put some effort into it. Remove hyperlinks. Change some words around. Remove words I know for a fact that you don't know (like quintessential). SOMETHING. If you are going to copy word-for-word, you could at least hand write it.
When you hand in something that you obviously printed directly from a webpage, it hurts. You might as well slap me in the face. When you had me that piece of paper what you are saying is, "I care so little about you as a teacher and your class that this was all the effort I thought your assignment deserved. I bet you are too stupid and/or lazy to even notice what I did."
Just don't do it.
**Note that this isn't really a wide spread problem, but rather a few isolated cases. It's just every time it happens a little piece of me dies.