What is the name of this black thing with a cable mounted on top of the helmet?

[hsinchong]

I'm not sure if that is a camera thing & some flashlight. Anyone help me ID it

 

[kaichu dento]

Pretty sure it's just a hair tie.

 

[AstroTurf]

Pretty sure it's just a hair tie.

yeah yeah, just like... Hello Kitty

LOLz

 

[letschat7]

Why does the FBI dress as soldiers? Is he JTTF?