Page "Internet Relay Chat takeover" Paragraph 7

According to Hypermedia Seduction for Terrorist Recruiting ( 2007 ), exploiting ICMP ping responses from broadcast addresses at multiple hosts sharing an Internet address, and forging the ping packet's return address to match a target machine's address, a single malformed packet sent to the " smurf amplifier " will be echoed to the target machine.

This has been used to take over IRC servers.