problem is your local isp sees you using Tor, so have to run tails in a VM and on the host tunnel all traffic through Jondo or something.
Just like if you're the only person in a country using Tor, writing about stuff internal to that country, yeah, they might notice.
In the Harvard case, as far as we know, they went to everyone running Tor and this kid freaked out immediately and it was case closed. If he has insisted on his rights and not talked about it, or provided another plausible reason (assuming he didn't leave evidence on his computer), they'd have had no solid leads. Or if he had used another network that wasn't Harvard's.