How do you catch name hackers?

Ive been a gm before and i know there is a way to catch name hackers but i cant find a way to do it and the one person that knows how to do it thats my friend wont tell me lol

dude... if im right... you are serieusly asking how to catch hacker on a HACKER forum?... -.-

WHAT THE F***CK! :O

Regards,

Demon

maybe he saying about me dam look he catch me ammmm