Cheating and plagiarism are two huge problems facing high schools. Long gone are the days when students would write answers on their hands. Now, students can send and receive text messages so quickly that even the most keen teacher might not observe this malicious behavior.
Nevertheless, one of my favorite weapons against plagiarism is http://www.duplichecker.com/. It is quite simple, paste an essay written by a student or upload the student's file and then press "Search". The website does the rest showing you if a student copied text from another source by providing the link where you can find the original article.
It is up to us teachers to combat plagiarism. However, we are living in an era where it is seen as legit to listen to illegally downloaded music and view bootlegged films--making it hard for students to understand the problems of plagiarism and cheating. We must work hard to educate students about summarizing text and citing sources correctly.
I hope you are able to use http://www.duplichecker.com/ as a deterrent to plagiarism in your classroom!