Because you have permission to use it.
Creative Commons (CC) information is shared with the world with the intent that you reuse it, change it up, and share it again. Just give credit where credit is due!
Because copyright law doesn't let you claim other people's work as your own.
Did you know you can get fined up anywhere from $750 to $150,000 for violating copyright? For each violation?! Yeah, you can. So cover your bases and use information legally. Using CC materials makes it easy to be on the right side of the law.
Because at Clackamas Community College, you are expected to use information ethically.
Using information ethically is part of academic honesty, which is what you agree to when you enroll as a student at Clackamas. (It's in your Student Handbook.) Using CC materials makes it easy to be ethical.