Tethering Notification Email from AT&T

Hello, this is my first post here and I appreciate anyone who can share their knowledge about tethering.  Yesterday, I received an email from AT&T that they will remove my unlimited plan if I don't stop tethering through my phone.  I haven't been using my wifi hotspot and didn't install any tethering apps.  So I called them this morning and ask why suddenly, they sent me a notification like that.  While on the phone it occurred to me that they must be looking at my Moto 360 as a tethered device, so I ask the lady on the phone if that's true.  She confirmed that AT&T does and I have to change to a plan that supports tethering to be able to use my Android Wear smartwatch.  Does anybody here have the same experience?  Thank you.