From a news report on Yahoo (here, if you're curious):
Sparking O'Reilly's ire was an episode of "Law and Order: Special Victims Unit" that aired earlier in the week, in which a crazed anti-immigration activist set out to murder the children of illegal immigrants.
O'Reilly slammed the show's executive producer Dick Wolf, calling him "defamatory and outrageous", a "coward" and a "liar". A quote from O'Reilly's show: "no one on this show has been allowed to demonize illegal immigants".
I can't embed videos, but here's O'Reilly going off about illegal immigrants:
http://www.youtube.com/...