Another major form of piracy is plagiarism. The stealing of someone elses ideas or work. The biggest category of people who fall into here are students. Another reason students may copy someone else's work is to sound more sophisticated hoping that if they use someone elses words it will sound better than their own. Generally, this provides an easy way for a teacher or the police to catch them.
Teachers also plagiarize rather frequently.
Very often a teacher will photocopy several pages from a book, in order to save the students the expense of having to buy the book for themselves. While this is a noble act by the teacher, in most cases, this is illegal. The third category of piracy is Software Pirating. There are several forms which this can take. A cracker is someone who has an in-depth knowledge of computers and programming.