[quote=@The Nexerus]
This is an actual, legitimate spoiler. Do not open this if you have not seen Season 5 Episode 5 of Game of Thrones.

[hider=Seriously.]
Maester Aemon: A Targaryen alone in the world is a terrible thing.
*dramatic pan to Jon Snow*

JON SNOW IS SON OF PRINCE RHAEGAR CONFIRMED[/hider]
[/quote]

it is known.