I've been a Verizon Wireless customer for a very long time (10 years). WiFi Assist is off. iPhone 6s+. I sleep within 15 ft of my WiFi router. I've noticed that my data usage is quite a bit higher than usual this month for the first time ever. Yes, I've seen people reporting strange usage recently as well (same for my boss who has Verizon - first time ever for him). So, checking Verizon's website - at 3am for the last few days, I'm using 40-150mb of data at 1am-3am (I go to bed at 11pm and wake up at 5am). My iPhone's cellular page now shows a discrepancy between what it thinks I've used and what Verizon thinks I've used (not a massive discrepancy, but it's there (first time ever)). Normally, I'd be at .2-.4GB of usage (I have WiFi everywhere I go) but now I'm almost at 1GB. I'm going to start sleeping with my phone in Airplane mode I guess and see if the usage continues? Doesn't bother me a TON but I give Verizon enough $ that this shouldn't be happening, imo (5 line family account). Edit: My wife's iPhone 6s+ line shows similar "mysterious" usage at 3am as I do even though we're on strong wifi. Hmmmm. Plot thickens. 2 lines with a 6 and 6s shows no mysterious usage. And the last line (a 6) shows minor usage at 3am (40mb).