MyPassport External 500GB HDD - Data Lost

Hey , my Hard Disk was filled with movies , tv shows and some pdf files . Its been in there for quite some time and nothing has ever happened to it . The drive is password protected with the help of the software that comes with it . However recently after i gave the hard disk to a friend , who said it worked perfectly and he could copy whatever he wanted i gave it two more friends who say that there is nothing in the Hard Disk . I too tried in my PC , the password works , Drive gets detected as usual , however now it says New Volume and there is nothing in the Hard Disk . I Have it confirmed from my friends that none of them formatted it , how can the data mysterically get erased like this ?? Please help!! 

Well dude, if I format my friends drive by error I will not be whiling to say I did it either :smileyvery-happy:

all the info you provided shows that the drive has been formatted.

You can try using a recovery software to restore the files

Sad but true, try using something like R-Studio, although its not a free tool, I find it works best for similar issues. Recuva or TestDisk are free however, so maybe try them first.