From an outside perspective... a bunch of new accounts are created within a very small time window, start posting on the same topic, using the same tags, with zero interaction with each other or the community. Said accounts immediately start receiving $2+ upvotes.
It quacks like a duck.
Incidentally, when I have taken online courses, we were required to interact with each other's work. This level of interaction (though still within the same group) would go a long way to making it look like legitimate usage and not AI-empowered reward farming.