You're probably think of this Ars piece: http://arstechnica.com/security/2015/08/new-data-uncovers-the-surprising-predictability-of-android-lock-patterns/ http:

You're probably think of this Ars piece: http://arstechnica.com/security/2015/08/new-data-uncovers-the-surprising-predictability-of-android-lock-patterns/ http://arstechnica.com/security/2015/08/new-data-uncovers-th...