I'm a developer that likes to mess around with hobby projects, and that tends to look a lot like illegal/stupid stuff. For example, I'll port scan my cloud services I maintain (explicitly against the rules) to verify it's configured properly. I'll create persistent connections to enable automatic deploys from home (again, explicitly against the TOS). I'll use torrents to download legitimate Linux ISOs (again, against TOS), and I'll use Tor to mess around with onion sites (again, against TOS). I'm building a P2P app, so there's a lot of unfamiliar packets flying about.
I'm an enthusiast, but I'm a respectful enthusiast, so I do my shenanigans off peak hours. If I did illegal stuff, I would hide it so the ISP doesn't find out.