do some challenges they will unlock it for you
-------------------------
Completing every challenge will unlock every title.
http://callofduty.wikia.com/wiki/Callsigns
Lots of people do by hacking very few probaly 2 or 3 actually have all titles
By getting into a tenth prestige lobby.
yes you do
There isn't one.
2 ways, you either get them all by completing there various challanges (YaY). or you can do the prestiage hack and get all of them like that (BOO!)
Yep. I have all of them, and I am Prestige 1 and Level 70, except the Prestige 10 title.
Yes you lose everything but titles and emblems
They can be found at the Call of Duty wikia. A link has been added under related links
You get the ability to unlock more titles, emblems and challenges even for guns The bad thing is you'll lose all your camos, guns and xp
Do it with a buddy play 3rd person cage match with each other.
no. for prestiging you only unlock new titles/emblems extra custom classes and a new symbol.