This document summarizes a research paper that proposes using a user's game-play activity patterns, specifically their idle time distributions, to identify users for network games. The researchers collected activity log data from 287 users of an MMORPG over 3 days. They found idle time was more diverse than active time between users and could be used as a distinguishing biometric. Their identification scheme uses consistency and discriminability tests based on KL divergence distances between users' idle time distributions, which they found could accurately identify users over 90% of the time with a 20-minute detection period given 200 minutes of stored activity history.