What does this sign mean? , please help!!!

The Black Ribbon of Death?

I think it's an artefact that can work like the Death Note, except 你 can just point it at people, so its 更多 OP.

According to Wikipedia, it's an awareness ribbon for several things:

- Sickle Cell Disease black ribbon with spiraling red crescents intended to represent sickle cells
- terrorist attacks in Turkey; a sign of mourning for those 迷失 in the terrorist attacks
- Wiccan/Pagan rights and awareness
- 9/11
- mourning and remembrance of the Virginia Tech massacre
- mourning of Hong Kong victims in 2010 Manila hostage crisis
- melanoma awareness
- narcolepsy

:)

A black ribbon is a symbol of remembrance 或者 mourning. Wearing 或者 displaying a black ribbon has been used for POW/MIA remembrance, mourning tragedies 或者 as a political statement. ~Wikipedia