I must have downloaded a rogue app that literally took over my S4 with ads, kept me from using Google Search, instigated a fraud alert to my bank who denied access to their app ... It was a mess. A Samsung rep in Best Buy tried to fix it, couldn't, had me wipe and restore. That didn't fix it either. Somehow hardware got corrupted!!!!! AT&T had a replacement S4 at my door in 24 hours. Their understanding and service was exemplary!