I can tell the other answers are by people who’ve never used cracked software serial and keys. Here’s the scoop.

DISCLAIMER: I in no way am encouraging piracy; this is an account of the means, the motives, and the culture. Back then I was a poor college student but very gifted with computers and I rationalized it as they weren’t actually losing money because I could not buy any of it. Pay the content creators; they work very hard to make their products.

Back in the good old days, approximately 10–15 years ago and more, it was extremely rare to have any malware attached. I started using cracks at age 12. Most of the games for the Apple IIe had no copy protection so me and my friends bought blank disks and had a swap meet.

A bit later before the rise of the net was the age of the BBS. Some had cracks but bandwidth was low and most had only a couple lines/modems so had little impact.

At around 1995 the way you got them was through lists of compromised FTP servers. Back then hundreds of thousands of companies and universities were installing various flavors of Unix servers. By default their FTP servers had an Incoming directory to which anyone could write files and once written anyone could read them. So people would find one of those servers, fill them up, then publish the URL. For a period of time between minutes and weeks they’d be up and eventually the sysadmin would find their bandwidth usage went through the roof and shut it down. Friday evening was a popular time as the admins usually wouldn’t see the spike until Monday morning.

Eventually the supply of usable FTP servers dried up and people switched to IRC which was the original internet service for real-time chat. People wrote bots that advertised their wares with up/down ratios. To obtain a package you had to upload stuff they didn’t have and then you could download a certain amount of bytes in return. It took a long time and was tedious but it worked and being distributed impossible to shut down.

Then a friend introduced me to Usenet. It’s the original BBS or forum internet service and like IRC still exists and is heavily distributed. That was a massive game changer. To this day you can still get almost any program, movie, album, meth recipes, kiddie porn, regular porn, porn involving chickens and black grandmothers: — every possible permutation of ***, size, age, race, object, color, animal, you name it. You want to watch hamsters go up rectums? They got it, ******s too. Hundreds of millions of posts on anything in the world. Sort of like Reddit but with files included. So you’d spend a couple hours poring through posts in alt/binary looking for interesting stuff. You couldn’t search thus the many hours to find what you wanted…it was all random.

Then companies started popping up off offering premium Usenet access with a special emphasis on alt/binary (underneath which ALL the files lived). They included extremely fast speeds, sophisticated access tools (search), and they kept no records of what you downloaded so if the government came knocking they had literally nothing to give them except the list of their users. Very safe indeed. Life was good for many years and then the criminal element discovered Usenet.

Let me address the motivation for the crackers over time as other answers adopt a, “If it’s free there must be some catch” attitude. This was the golden childhood of the net. Crackers received three benefits from their work, the crack itself, access to gigantic private FTP servers in exchange for the new crack, and most of all accolades from their social network. Crack groups competed heavily to pop out a crack to the latest software before others, found alliances and enemies, and advertised for anyone with access to pre-release content. Since it takes a couple months to produce enough disks and package and ship them to stores for the release date the master disk was finalized before that process. Anyone who could steal a copy gained large benefits from the crack groups. It was routine for games, movies, and albums to appear 1–2 months before they went on sale. Access to the methods I’ve described above were very technical and only a handful of real geeks had the knowledge to use them. Sinc