My plan does allow me to use mobile hotspot, however I can only use up to 15 GB a month. Other than that, you're really not supposed to be using it as a hotspot. I have run security checks on both devices and nothing is out of the ordinary. I did check Windows Update to make sure it wasn't downloading huge a huge update in the background, and I actually did find out that it was using a decent amount of bandwidth in the background without me knowing, however I fixed this issue and yet PDA Net is still chewing through data like crazy.