So, literally as we rang in the new year here in Australia, my phone started acting up, and wouldn't let me swipe to unlock or anything. Screen would turn on, home screen wallpaper would appear, then turn off. I'd try turning it on again, and the same behaviour, or sometimes even just straight to homescreen wallpaper. Notifications for messages still seemed to be coming in, but I couldn't even acknowledge those on the lockscreen. All touch input seemed to have been lost. Screen seemed to get quite hot too - probably CPU or GPU. I rebooted the phone several times and still no better. I'm on a rooted Note 4, running 5.1.1. I booted into TWRP and cleared both the cache partition and the Dalvik cache, but still no better. After sleeping on the problem, I decided to start renaming potential trouble apps (apps that run visible services, like Tasker, Join, etc) using the TWRP file manager, one at a time. /data/app/com.joaomgcd.join-2 happened to be the first folder I moved out of the way and, et voila! it worked again. Any chance of a bug in the code that timebombed on Jan 1st 2016?