Television and newspapers have turned the term into a digital demon, someone who takes over computers and uses them to rob banks and steal military secrets. Most of them simply exploit holes in the security of common Unix-based systems. While they can be dangerous, this group is kept mostly in check by the hundreds of system programmers and system administrators who do battle with them every day. Though they wish otherwise, they are mostly harmless, not even qualifying as a mild annoyance to anyone who has kept up with security patches. They rely on the fact that if you look at enough systems, you're going to find a few that are vulnerable.
Pirates are fairly benign as a group, at least by comparison to serious system crackers.
They limit themselves to simply stealing popular software, and perhaps distributing it to others, often giving it away for free. When and if they're caught, they argue that they aren't depriving anyone of anything, since they're simply making copies of software, not taking it away from anyone, and the people they give it to wouldn't buy it anyway. Some provide sophisticated arguments claiming that they are actually helping the software industry in one way or another. But there is one other group, the ones who take it upon themselves to supply the pirates with much of their software. These are the program crackers.