The work you hand in must be strictly your own. Plagiarism is included in this definition: claiming as yours work that is not your own; i.e., not just copying from your classmates, but also copying from the Internet or other sources without using appropriate references.
There are many programs and search tools available not only from your classmates and other students, but also on the web. Of course, I am as aware of these things as you are---maybe even more than you are.
If I suspect that you are not doing your own work, I will ask you to come see me so that we can discuss the matter. If you cannot convince me that my suspicions are unwarranted, then I may have to send your case to a disciplinary body; and you risk being expelled from the college.
Please, let's not go there. I've been there before, and believe me, it's not fun for any of us.
Brooklyn College Policy on Academic Integrity
The faculty and administration of Brooklyn College support an environment free from cheating and plagiarism. Each student is responsible for being aware of what constitutes cheating and plagiarism and for avoiding both. The complete text of the CUNY Academic Integrity Policy and the Brooklyn College procedure for implementing that policy can be found at this site: http://www.brooklyn.cuny.edu/bc/policies. If a faculty member suspects a violation of academic integrity and, upon investigation, confirms that violation, or if the student admits the violation, the faculty member MUST report the violation.