Recently I have been having issues where my phone will lock up at the lock screen, I cannot get out of it by swiping, if I try to shut down or reboot, I get the menu when I click on the power button, however, I cannot choose an option. Have to pull the battery to get it back. It seems random, I use my device pretty heavily, the issues happen sometimes when I pick it up after noon using it for a while. I am using Nova as a launcher and I do use Sonos quite a bit, no games, standard messaging app, standard email client, Hmmm maybe it's Facebook?