Fethullah Gulen is a reclusive, cult-leader-style billionaire, who lives in exile in America. He owns a vast network of educational institutions worldwide, as well as many other companies, and has built up enormous political influence within Turkey and outside of it. He advocates the islamification of societies through the stealth infiltration of state institutions, but eschews terrorism and overt hostility to other religions.
Work patiently and creep silently into the institutions in order to seize power in the state.
He fled Turkey in 1999 while under indictment for plotting to undermine secularism. Those charges were thrown out in 2006 when a more Islam-friendly government was in power and according to a Wikileaks cable, Turkish President Gul is a Gulenist but Prime Minister Erdogan is not.
The same Wikileaks cable also provides some interesting insight on the extent of the Gulen network's penetration of the Turkish National Police (TNP):
Gulenists also reportedly dominate the Turkish National Police, where
they serve as the vangard for the Ergenekon investigation --
an extensive probe into an alleged vast underground network
that is accused of attempting to encourage a military coup in
¶2004. The investigation has swept up many secular opponents
of the ruling Justice and Development Party (AKP), including
Turkish military figures, which has prompted accusations that
the Gulenists have as their ultimate goal the undermining of
all institutions which disapprove of Turkey becoming more
visibly Islamist. (COMMENT: The assertion that the TNP is
controlled by Gulenists is impossible to confirm but we have
found no one who disputes it, and we have heard accounts that
TNP applicants who stay at Gulenist pensions are provided the
answers in advance to the TNP entrance exam. END COMMENT)
The cable also spoke about the climate of fear surrounding the Gulen network in Turkey:
Most discussions in Turkey which touch on Gulen tend
to be somewhat delicate and deliberately artful. Our
interlocutors often seem reluctant to express their views,
seemingly uncertain if it will rebound on them to their
Meanwhile, according to the now-embarrassing Guardian newspaper, there's no problem with free speech in Turkey; and anyone who insists that there is must be part of some big Jewis... oops, I mean Zionist conspiracy.