In White Dwarf issue 229 there is an article by David Cain concerning
Night Goblin Fanatics, discussing their uses, how to defend against them,
and also how their special rules work.  Unfortunately, Dave, who is 
generally regarded as a good player, is sorely confused on this last
item (basically, he knows bugger all or has been seriously misled).
He makes a number of incorrect claims about how the rules work, which,
if used, drastically alter the mechanics of fanatics...  I take it
upon myself, as Orcs and Goblins are my favourite army, to correct his
mistakes in the interests O&G players (and their opponents) everywhere.

His first incorrect claim is that the fantatics may only be sent whirling
toward the unit which caused their release.  The rules do not say this.
The fanatics must be sent towards the enemy, but which enemy is left
entirely to the discretion of the owning player.  David Cain's article,
if factual, would open up some very abusive strategies, such as whipping
around one flank and forcing fanatics to run down your own battle lines,
through several units of greenskins.  Whilst undoubtedly humourous, this
is most certainly NOT supported by the rules.

Next, David makes the claim that once a unit has crossed the fatal 8"
line and released the fanatics, then no other unit may, in that turn,
cross that 8" line.  This is utter nonsense.  There is a line in the
rules which says that enemy units may not move into or through the
fanatics themselves, but nothing which even remotely suggests that they
may not move to within 8" of the goblin unit thereafter.  In fact, there
are rules which state that a unit may indeed move closer to the
goblin unit - the unit that caused the release of the fanatics, if
charging, has the option to continue to charge.

Lastly, David says that when a fanatic would end it's movement inside a
unit, it is placed on the far side of it because it's silly to assume that
the unit will just sit there.  Now, while this isn't addressed in the rules
(and it should be, along with random release from suddenly appearing 
enemies), it HAS been answered by one of the designers.  Someone on the
Warhammer mailing list asked, and got this answer, which may be found
in the mailing list's large FAQ file:

<<
Q: When a Fanatic ends its movement inside a unit, what is done? 

A: Place the Fanatic right next to one of the sides of the unit (on the outside
of the unit). Choose the side that is closest to the Fanatics end position
in the unit. [Primarch] 
>>

(the [Primarch] tag indicates an answer from a designer such as Jervis Johnson,
Nigel Stillman, or Tuomas Pirinen)

Not a big difference, but it can matter, and this is an answer from a 
designer rather than an opinion from a player.

Some people will have the impression that because the article was in
WD it must be correct.  This is not so, and a simple reading of the 
bestiary entry for fanatics will show this.