By chance, in the last day or two I have heard of several academic integrity violations. Namely, when papers and projects were checked with Turnitin or just Google, the source was discovered. Often, substantial quantities of a paper or project are lifted from some source with no attribution, or with a general attribution but with no quotes.

What's happened is that there are people who make money not only from selling papers and projects, but other people (Google, Turnitin) from web search and other such to find similar items to what you are looking for. The search people are very smart, very motivated, and quite powerful computationally. Moreover, other "borrowers" leave their work on the Net, so that even if you have borrowed from a secure source, there will be footprints by those less careful. It's sort of like inside trading, where one of the beneficiaries just can't help but tell a friend.

Professors are encouraged to use these search services, and the services are becoming much more automatic--and competition will make them much more effective. Bing vs. Google.

By the way, there way a time when students would say that they did not know this sort of borrowing was not ok. It was part of their culture. (Think here of what happens in popular music and mixes. See "Steal This Music," by Joanna Demers, where the traditions are more deeply explored. Or, look at the wonderful literature on book publishing's early days. And quoting from Scripture or authority is often done in speeches, without acknowledgment.)

But, at least in school-work and in scholarship, such unacknowledged borrowing is a violation of academic integrity and a form of theft. Acknowledged borrowing with proper references is in fact the nature of scholarship.