At Rhode Island College, a freshman copied and pasted from a Web site’s frequently asked questions page about homelessness  and did not think he needed to credit a source in his assignment because the page did not include author information.

At DePaul University, the tip-off to one student’s copying was the purple shade of several paragraphs he had lifted from the Web; when confronted by a writing tutor his professor had sent him to, he was not defensive  he just wanted to know how to change purple text to black.

And at the University of Maryland, a student reprimanded for copying from Wikipedia in a paper on the Great Depression said he thought its entries  unsigned and collectively written  did not need to be credited since they counted, essentially, as common knowledge.

Professors used to deal with plagiarism by admonishing students to give credit to others and to follow the style guide for citations, and pretty much left it at that.