It's just the way script kiddies and wanna-be's type on the internet. Doing things like dEliBeRaTelY MiXInG cASE, or using numb3rs 7o r3p1ac3 l3tters. (3=E, 7=T, 1=L, etc.)

A lot of hackers and script kiddies like to use the term "Elite", often shortened to "Leet". So E-1337 is a pun on the word "Elite" written in script kiddie lingo.

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Tony Fabris