I've been involved in the last couple of years, to a greater or lesser extent, in three investigations of student misconduct. All had one thing in common: use of the internet either as the medium of the crime or to produce the evidence that nailed the worthless wretch.
Case 1. Towards the end of the Summer I received an email from a student saying that they would be unable to submit their dissertation because they were having emergency surgery for what by common consent would be described as a very distressing condition. Usually in these cases there is little to worry about academically. You provide medical evidence - normally certification of some sort from your surgeon - and the Proctors decide what should happen. Nobody is ever disadvantaged if they have a genuine (certified) medical problem. In this case the medical evidence was slow to appear. Weeks and then months went by, emails were exchanged, letters were said to have been sent but never arrived. It all began to look odd. Eventually a letter did arrive, purporting to come from the student's surgeon. As soon as I saw it I smelt a rat. Together with one of our departmental assistants I started to take a closer look at the document. A trivial internet search showed that the logo on the letterhead was real but the address of the clinic though real didn't seem to be the address of a medical facility. Google maps and streetview allowed us to establish that the address was in fact an apartment block. It was also easy to establish that the phone number of the "clinic" was registered to a cell phone - somewhat unlikely for a medical facility. And there was more. We were able to check online if the "surgeon" was licensed by the appropriate medical authority - no person of that name was registered. Finally, and hilariously, the student's Facebook wall recorded them arranging to play tennis a day after they came out from under the knife - which, given the nature of the surgery - seemed, to say the least, physically unlikely. The Proctorial investigation found the accused guilty of misconduct and slung them out of the university.
Case 2. One day I was copied into an email from an aggrieved journal referee complaining that a student had more than once submitted articles for publication that were little more than crude cut and paste jobs from other people's work. On close examination there was little doubt about it. The student had an apparently impressive CV full of published pieces in relatively obscure internet journals that were blatantly plagiarized. The way that it was done was so artless that it was difficult to imagine how they had thought they would get away with it. To cap it all off it turned out that papers turned in as part of their doctoral research had been plagiarized in the same fashion. At no point did the student admit their guilt, even when presented with the evidence. Instead they concocted a fantastical story of coincidences that collapsed under the weight of its own contradictions. Eventually they withdrew from their studies on "medical grounds" and thus preempted the inevitable expulsion.
Case 3. I received an email from an academic in another university who has a research interest in academic fraud. As part of a research project they monitor "essay mill" websites and he had noticed that somebody was touting a contract to write a paper on a subject and using materials that derived from a course I used to teach which this year was being taught by a colleague. Signing up for the site I got access to the bidding process and learned something about the monetary worth of my exercises. The range seemed to be from £60 for an effort promised by somebody who clearly couldn't write English through to about £160 for one written by somebody who had a few recommendations from satisfied customers. I gather the Proctorial investigation into this is ongoing, but the outcome so far has been a lot of inconvenience for the vast majority of honest students who had to rip up the work they had already done and sit a new assessment. I hope if the culprit is ever discovered they are named and shamed and their infamy follows them ever after.