Below is bit of history on the actual Lin Kuei of old:
Lin Kuei
From Wikipedia, the free encyclopedia.
The Lin Kuei clan, also known as forest demons, were an ancient
secretive cult that operated in northern China many hundreds of years
ago. This individual clan's past and history is shrouded in mystery.
However, it is believed that they resided in the deep parts of the
forests, and they captured unsuspecting travelers and forced them to
breed with the clan in order to grow their numbers and members.
Children are usually brainwashed and were chosen at birth to work as
spies, assassins, and thieves for the benefits of the clan (similar to
the thugees in India). When more and more people began moving into
their territories, their numbers dwindled and went their separate
ways.
Probably during China's Tang Dynasty, some of the Lin Kuei members
traveled to Japan to teach their secret arts and ways to the local
villagers. Over the years, many of these methods were used and were
incorporated into the art of ninjutsu. It is believed that some Lin
Kuei stayed in Japan and made a living as mountain hermits or priests,
known as the Yamabushi. They have since disappeared. Other Lin Kuei
traveled to Korea and continued their teachings.
It is believed that they were monks who practiced their ways and
customs. They lived secretly in caves and in forests for centuries.
After the clan's decline, the last Shr-lin (grandmaster of the Lin
Kuei) moved to the United States to reform the clan. The last Shr-lin
died during the 1970's, and since then, a clan member known as Li
Hsing, who claims to have been a friend of the last Shr-lin. Two books
written by Li Hsing are China's Ninja Connection and The Combat Skills
of the Lin Kuei: Heritage of the Ninja.
The clan used An'Chi, which is a secretive Chinese art and a distant
cousin to ninjutsu. This unusual Chinese style concentrates on hidden
weapons and gadgets, but it is taught in secrecy. Its reliance on
exotic tools makes it similar to ninjutsu, and An'Chi exiles in Japan
might have been among the original ninja associated with Lin Kuei.
Like ninjutsu, it concentrates on the use of deception, guerilla
warfare, tricks and traps, and so forth.
This style concentrates on the use of throwing weapons. It is said
that masters of this style can turn any common household object into a
deadly weapon. This form also specializes in concealing techniques for
small throwing weapons, such as spring-loaded arrows, shuriken
disguised as common items like coins, harmless-looking darts, and
countless others. In combat, an An'Chi specialist will try to take his
opponents by surprise. He will seem helpless. Suddenly, weapons will
appear in his hands, and he will start raining them on his enemies,
aiming for vital points. An'Chi masters are also well-known for
filling their hiding places with exotic booby traps. As a style,
An'Chi is rather incomplete and was probably not meant to be studied
alone, rather in combination with other styles, particularly external
kung fu forms (Not unlike Ninjutsu) This style was common among the
Chinese equivalent of the ninja– the Lin Kuei.
In Batman Begins, it is more likely that Bruce Wayne is training under
the Lin Kuei rather than ninja-style, as Ras al Ghul's cult is an
ancient Chinese cult that also incorporate various kung fu styles into
their curriculum.
The idea of the Lin Kuei soon became most popularly known in the hit
fighting video game, Mortal Kombat, in which the Lin Kuei were
portrayed as a clan of Chinese ninjas. The Lin Kuei known in the game
are Sub-Zero, Sektor, Cyrax, Smoke, and Frost.