Hackers by definition are any programmers.
As in program hacking
On the other hand, forcing your way into someone elses computer without express permission is called cracking, or more to the point Criminal activity.
In which case:
1) I can hack in assembly, C/C++ and java, perhaps HTML if you consider that a programming language, which I don't.
2) I haven't broken into other peoples computers, not that I have tried, but if a 12yr old with a cable modem and a bunch of tools can do it, I feel fully assured that i can learn any necessary skills if i applied myself to it.
But why bother? Just grab one of the 100's of viruses that people send you every week, dissasemble it, and re-program it in assembler for your own use, then send it out into the world wide web