Where can i find them (Trying to get trophy, last one i need ^^)
Ive hacked 15, i honestly cannot find any more..
There like stealthboys.. Impossible to find once you've already found a few!

You're not trying very hard. There is a locked terminal in almost every building. Vaults have a bunch as do office buildings.
the http://fallout.wikia.com/wiki/New_Vegas_Terminal_Locations lists 34 of them. There are more.

REPCONN, BOS Bunker in Hidden Valley, and the NCR Embassy are the ones I can think of offhand where I've seen more than one.

I will tell you where they are not. They are not in the General Section which is not to be used to discuss spoilers or ask for spoilers.

I will move this now so I don't have to warn folks for posting off topic.