You, only cooler, edgier, and often ruder. A Darker Me is generally the person you would be if you weren't the more cautious, inhibited and boring person you actually are. Most online personas include at least a little bit of A Darker Me, and some, most notably the Troll, include a lot of it. A Darker Me is like the GIFT in that it allows people to say things they would never say in real life, but is not limited to profane or offensive statements.
A Darker Me is one of the main appeals of the Internet in that it allows users to leave behind their normal fears and speak their minds. Most posters eventually learn that too much A Darker Me by those involved derails even the most steadfast discussions and begin to revert to their mundane selves, in action, if not persona.
It should be noted that A Darker Me is not limited to the Internet, as most people do the same thing when they are talking to strangers — albeit generally to a lesser extent, since the stranger can still punch them in the face if they go too far.
See also: G.I.R.L., GIFT, Beneath the Mask, Troll, Griefer, and Mean Character, Nice Actor. Closely related toWhat You Are in the Dark. Compare Became Their Own Antithesis and Maddened Into Misanthropy. Not to be confused with the other kind of Darker You. Or the otherother kind for that matter.
XXX Holic featured a sub-story about a woman in Hideki's school who, thanks to a winged parasite, slowly lost her inhibitions. Instead of being nice and sociable, she became progressively more angry and violent until she nearly killed a person.
In A Voice In The Dark, when Zoey goes to a costume party dressed as Cleopatra she deliberately makes herself unrecognizable so she can observe the party without being recognized. She acts different as well, flirting with boys, makng small-talk, and dancing. This is all in stark contrast to her normal reserved nature.
The red pills of The Matrix. Before their introduction to the Real World, they were hackers, geeks and other freaks. This makes it obvious why, when they go back into the Matrix, they all wear longcoats and sunglasses.
The Hiver in A Hat Full of Sky is an Eldritch Abomination that is considered extremely dangerous to the humans whose minds it possesses. It actually tries to help them gain what they wish for, but it doesn't understand the difference between dark desires that are suppressed because the person knows they are not right and those that the person on the whole really wants fulfilled. Its victims are eventually driven insane and destroyed, but before that, they will presumably have become darker themselves, so to speak.
On Caprica, New Cap City is a virtual environment built around this concept along with Video Game Cruelty Potential, where the whole point of the game is to have fun without getting killed by someone else's idea of fun. Everyone gets access to the guns, drugs, cash, and sex they could want, and the only major consequence being that if you're too slow, you die and can never return.
In Screenwipe, Charlie outright admits that his default comic persona, a misanthropic Man Child, is one of these, and while there are traces of his real self in it, his real personality is much more nice and boring. He admits this in character.