I am a long time Verizon customer....but only got a jetpack a few years ago for my wifi. There is just me using the data (at least I think?). I do NOT stream music, videos, nor do I watch many youtube videos...and I have had several instances where my jetpack says I've used more than 6 GB. I surf the web, email friends, download a receipt or two per month, and play some solitaire.....how could I use more than 6 GB of data???? And of course, many of these messages have come in the night, when I'm not even on the computer/wifi! I do have an iphone 5s and have turned off the cellular data.....I do text and call friends...but do not watch videos nor stream music with it either. The first time this happened I upped my data immediately thinking it was me.....but after much exploring about data usage and posts about the jetpack, I think it is the jetpack's problem. I have now upped my data to 10 GB plan.....to try and be safe (I have upped my data plans several times and then dropped them back due to this issue). I guess I should consider myself lucky that my overages have been small compared to some of the accounts I've read about!
Sometimes my computer security says that the jetpack is NOT SECURE? Maybe that is when someone/something besides me is using data from it? And I have tried turning the jetpack off when I get one of those overage messages....
Don't know if I will stay with jetpack wifi....there have been other issues as well (the turning off/going dormant when it was being used...though I finally found a post on how to fix that).....NOW am waiting to hear solution from Verizon on unexplained data usage on many of their jetpacks!!!!! Or maybe someone will find solution for them!
