Sudden / random spikes in Listens this Fall

We are wondering if there is any way to determine how/why there is a periodic spike in Listens in the past couple of months — perhaps it is due to a class or group that has begun to listen in at the start of a school year, or similar, but the stats show that 93% of the Listens are via an “Unknown” player. Is there any way to discern if the Listens are legit or not? We are hoping it isn’t a nefarious entity trying to run up our bandwidth bill or something like that… Thoughts?

The page I need help with: [log in to see the link]