Generally accepted internet rule that states that there are no girls on the internet. Usually used with rule 34.
An actual real internets girl will typically NOT engage in explicit description of her sexual organs or their current, past, or projected future engagements. For example, a real Internet girl might mention she is on her period. This is fine, well within realgurl guidelines and a clear warning to leave the immediate vicinity. However, she is unlikely to describe the vile seepages involved. Eg: "The crimson ichor of my wymenhood cycle is leaking from my puffy, raw vagina (That aches to be fucked)."
'There are no girls on the internet' first gained popularity among what indisputably is the majority internet user demographic, the chronic unlayable.
A: Hey, I just spotted this hot chick!
B: Rule 16.
Rule 16 states that there are no females on the internet - specifically in role-playing games and chat rooms.
Expanded Rule 16 states that:
a) All internet men are men
b) All internet women are really men
b) All internet children are policemen
Player 1: Did you check out Rocket Dog' profile? She is so hot, so I PM'd her and she is sexy cool!
Player 2: Dude, remember Rule 16. She's really a 40 yo dude in his living in his mom's basement!
Player 1: No! She's real and she likes me!
Rule 16 states that "No boner shall go flaccid without proper ejaculation." This means that a boner must reach ejaculation by means of vaginal, oral, anal sex or by masturbation before it is aloud to return to a flaccid state. Rule 16 applies at anytime of day, in any location or situation. Unorthodox methods of ejaculation are encouraged.
Mike: Jon has a boner! I see it in his sweat pants!
Jon: Damn. (Jon applies Rule 16 and pulls out his dick and jerks off)