Yes Justin Bieber is dead. If you play "Baby Baby" backward, you can hear "Bieber is dead"---oh, wait a minute--that was Paul McCartney and any number of his songs and albums!
http://aboutthebeatles.com/paulisdeadclues.php
http://www.funtrivia.com/en/Music/Paul-is-Dead-Hoax-10840.html
As of this moment, the Biebs is alive and well. You can't believe everything you read on the Internet.
However, if you ever want to know if a rumor is true or not--try this site. It debunks (or verifies) urban legends, rumors, hoaxes, and stuff like that. For instance the "Bieber is dead" rumor has been around for years already. In the one below, he dies of a drug overdose, but I've heard ones where he gets killed in car wrecks, bus and airplane crashes, knife fights (!), etc.
http://www.snopes.com/inboxer/hoaxes/bieber.asp
The latest rumor of Justin's death popped up about a couple of months ago, and is still going strong (in various morbid ways) if any of the numerous hits I got from Googling indicates.
Unless you read it or see it on a reliable news source (and directly from their site or station--not some other site or tweet claiming they saw or heard the story on CNN or something), don't "belieb"
it.
Sorry, couldn't resist the pun.