TurnItIn is a widely used program that is designed to assist students in their academic writing. It has several features that detect similarity to millions of pages of web content. It will allow you to see what portions of your paper need revision and how to improve the quality of what you write.
*This is a tool commonly used by colleges and universities to detect plagairism. Penalities for plagairism at the college level are severe, including expulsion with no financial reimbursement. Applying to another college will be extremely difficult as they will want to know the reason why you left your former school.
It is also designed to protect the intellectual property of others, including you!
Remember, there are six protections the law provides you as a copyright holder:
Reproduction Public Performance
Adaptation Public Display
Distribution Digital Transmission Through a Sound Recording
A great read:
See here for an excerpt: Conning Harvard by Julie Zauzmer.
Be sure to keep scrolling, many empty pages will appear before the introduction text.