BAD THINGS. Okay, not that bad but it is against our rules.

Each time you ride the train, we do a quick random check to see if you have unsubscribed from people who you were subscribed to when riding the train in the past.

If we find that you unsubscribed from someone, you get a Strike against your account (your SubscriberTrain Account, not YouTube Account)

Once you get 5 strikes, you are banned from using our service. 

Why? Because that's the way it is. The whole point of riding the train is gaining subscribers. Do you want people unsubscribing from you? No. And they don't want you unsubscribing from them.