Not Your Personal Army

Not Your Personal Army, often shortened to NYPA, is an Internet meme which serves as a catchphrase used to imply that the community a person is requesting aid from refuses to help them in any way. It is often used as a reply to site raiding threads.
The usage of the phrase begun on 7chan's now defunct invasion board, otherwise known as /i/.
Taking note of the success rate of /i/, people often requesting help from this board for their personal problems and vendettas. As these issues do not usually matter to anybody else on the board, the phrase was often used as a reply to the original poster to signify that the board refuse to provide aid to someone.
The phrase eventually spread off to other sites and chanboards, most notably 4chan (/b/ is not your personal army.) where it is now a commonly used phrase.
Somewhat ironically, it has been claimed that 4chan was a primary motivator for the creation of 7chan's /i/ board.
Eventually, the phrase was seen as a humorous catchphrase, being used in image macros where the phrase's original intent is not even implied.
A definition for "NYPA" was posted to Urban Dictionary on December 8, 2007.