From the doc: ' Ping was designed with the best of intentions, allowing users and admins alike to test their networks. Unfortunately, too often it is associated with Denial of Service attacks, and is often disabled (at least for non-root users). With the standard ping distributed on most systems today, a non-root user can easily cause DoS attacks even without the -f flood option. What admin hasn't logged on one day to see twenty 'ping -s 65000' processes happily sucking up your network resources? It seems anywhere there is ping and a non-trusted user, chaos ensues. Not to mention having to explain why your box was responsible when the person being hit calls you or your uplink. What a headache, no wonder people disable ping. The goal of this program is to permit benign activity from well-meaning users while preventing malicious users from flooding others, and logging such attempts.'