Whenever I sit in the back of a lecture where students are using laptops to take notes, I notice a significant number of devices being used for extracurricular

Whenever I sit in the back of a lecture where students are using laptops to take notes, I notice a significant number of devices being used for extracurricular purposes: messaging apps, web browsing, etc.. The most hilarious (perhaps egregious, if you are instructor) examples were watching Netflix during a lecture, though youtube is also pretty common. The most depressing were gambling sites. Phones are usually set to messaging/youtube/twitter/etc.. Mobile games seemed rare, surprisingly. An interesting bit is that email seems much less popular than messaging apps. In professional or academic conference sessions, most laptops seem to have an email app open. I expect professionals and researchers rely more on email. I think someone once suggested that you could automatically monitor and rank conference session engagement by measuring wi-fi usage. In any case, I can understand why some lecturers might advocate blocking wi-fi and cellular service during lectures. Though I sat in on one course where every student had a web app where they could follow along with the lecture and examples and also provide immediate feedback (e.g. solving short problems or answering questions addressed to the class) to the instructor.