Slang in "1337 speak", which is a language used by people chatting online.
The etymoligical roots of j00 are quite unclear, yet it seems that it is derived from accents of the english that are found humourous by some and made into a joke which soon developed into norm. Such is the history of many internet slangs.

-- GRAMMATICAL USAGE --

j00 should NEVER be used as a subject, only as an object or within a prepositional phrase. If needed to be used as a subject, it should ALWAYS be replaced with "you" or another 1337 speak equivilant.
(ie. "Are j00 there?" is incorrect. "I pwn j00" is correct.)

j00 is often used in conjuction with mathematical signs of comparism, such as "=" (equals), ">" (greater than), or "<" (less than). Again, in these cases, j00 is the object and is always on the right side of the sign. There are some cases where it is okay to do otherwise, as this rule is somewhat lenient. ">" is most frequently used, and is read as "owns"
(ie "Rockets > j00" - read as "rockets pwn you", "j00 = stupid" - special case)
he obliterated j00
giant sticks of dynomite > j00
by Justin Le May 12, 2005
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1337 speak for the word "you".
OMG I PWN j00!
by spikeboy April 10, 2004
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1337-speak replacement for "you". Usage is correct when used to replace the "-ed" of a past tense verb followed by "you". Commonly misused as a simple replacement for "you" regardless of the preceding word.
For example:

I h4x0rd you -> I h4x0r j00
I pwnd you -> I pwn j00

However, the following examples are both incorrect:

I pwn you (present tense pwn) -> I pwn j00 (tense changes)
I pwnd you -> I pwnd j00 (redundant)
by JCipriani August 4, 2006
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1337 version of you
OMFG J00 ARE TEH N00B!
by SuperSonicX September 16, 2005
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(1)1337 speak for a Jewish person.
(2)1337 speak for "you"
Are j00 a j00?
by Anonymous December 8, 2002
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1) The addition of leetness to a sentence, by replacing the word "you". Leeter than joo.
2) Could also be used to leetifiy the word "Jew".
1) I shoot j00! j00 go down!
2) Hitler liked to kill j00s.
by Andy123 May 8, 2005
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1.- A way of saying "You" used by a n00b or 1337 trying to copy a n00b
2.- Not m3
omg j00 r t3h n00b35t p3rs0n 1n da w0rld
by Sinisterff July 29, 2006
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