Tracking a target as it moves in monitored area has become an increasingly important application for wireless sensor networks (WSNs). Target tracking algorithms continuously report the position of the target in terms of its coordinates to a sink node or a central base station. Due to the rapid development of WSNs, there is no standardized classification of target tracking algorithms. Some of those classifications consider scalability, energy consumption and accuracy; other classification considers network topology, position of target, mobility of target/object etc. In this paper, we have considered target tracking algorithms of WSNs from the security point of view. We have compared and discussed problem of security in the most important target tracking algorithms for WSNs. To the best of our knowledge, this is the first study that analyses the target tracking algorithms in terms of security.