I saw all the posts about other people saying this (including the guy who got charged for gigabytes of international data roaming). I stupidly continued to use adblock.
I know, you're going to give me the link to the faq which mentions all data usage would be categorized as adblock. But there really is a bug in adblock which uses a ton of data.
Yesterday I went out to the stores for a couple hours. During my trip i got notified about data usage and found adblock used 500mb in under 2 hours. I'm rooted. I've got a clean rom. I know exactly what is running. I've disabled apps that run at startup. I've hibernated background processes with greenify. There no crap on my phone. I wasn't even using my phone during this time. I know adblock wasted all my data, nothing else. Luckily I wont get billed, but tmobile is going to throttle my data to about 0.0001mbps for 4 weeks. I hate you guys