neochat error

[DJFuji]

[19:28] *** :Sterling.VA.US.UnderNet.org 451 djfuji djfuji :Register first.
[19:28] *** :Sterling.VA.US.UnderNet.org 465 djfuji :Spoofed IP.
[19:28] *** Error: Closing Link: djfuji by Sterling.VA.US.UnderNet.org (K-lined)

wtf does this mean?