It was more the dicks showing up in class unprompted. Then, it was people sharing links to shock sites. Now we have to worry about people stealing information. That was always a thing, it's just a lot more common now.

Edit: I also have to admit, I remember helping the teacher enough with their computer to get Admin privileges by using their console. It was literally stuff liking helping them make a PowerPoint full-screen. I'd download games and then dispense them through little known shared files on the network (usually old forgotten projects). I'd also save shortcuts to google proxies. In hindsight, that was exactly the kind of thing they're probably trying to stop. I was pirating stuff at a young age. I definitely could've downloaded malware and shared it with the network.