A Bievert is a word that derive from (Justin)Bieber+Pervert.
A Bievert is that kind of guy that posts comments on youtube on any kind of video ruining the joy by seeing Justin Biebers name along with such amazing and beautyful songs and videos or trailers.
Basically this word should be used by Justin Bieber Haters Hater. So you call a bievert someone who uses Justin Biebers name in a place where it does not belong.
In the Death Note anime videos:
Bievert: "Light forgot to write one name, Justin Bieber."
Sick of Bieverts: "God man you are such a Bievert I was just enjoying this AMV that name should not appear in such a place man, please never do that again!"
Bievert: "Why Justin Bieber gets 128321 milion vies and this song only 30k?"
Bieverts Hater: "You are such a bievert, can't you understand that I want to enjoy this amazing song and that names place is not here."
Bievert: "This guy is a lot better then Justin Bieber who's just a girl."
Sick of Bieverts: "You are such a dumb bievert why the hell everywhere i go i see this name? Please understand that his place is not here!"